Remington740 / 740A / 742 / 7400
Model 740 & 740A : There seems to be lots of missing information as to the relationship of the 740 and the 740A. This article will not be a collectors directory, but geared more toward a gunsmith's perspective. Below I will try to describe this as I see it as there seems to be little in print covering this subject.
The Remington model 740 semi-auto was named the Woodsmaster, and came with a 22" barrel with a detachable 4 shot box magazine, being introduced in 1955, three years AFTER it's companion, the 760 pump.
This model 740 was probably only initially produced in 30-06.
Initially the buttstock
wood was plain uncheckered walnut, with no grip cap and sported a cast aluminum buttplate. As seen in the photo below, the stock has a
lot of drop in it, making for it rather low for a good fit if using a scope. Original forearms had finger grooves running
horizontally most of the length, weakening it.
It was not supplied with sling swivels. Rear sights were dovetailed into the barrel for the Remington’s unique
rear sight (shown below), while the small front ramp was silver-soldered to the barrel and dovetailed for the
Initially the early production, (740) had a receiver mounted pivoting bar type ejector, which is odd that they did not follow the improved bolt head extractor/plunger type ejector used on the already in production 760 in 1952, but read on as I will try to cover that later.
In the photos below you can see the definite visible differences as compared to the later type related to the pivot mounted ejector mentioned in this article. The material in the side of the receiver where this ejector was mounted was not thick enough to allow the whole pivot hole in the ejector, with the actual hole in the ejector being a partial hole more like a C with these small lips being the retainer on the pivot pin. This location then became a weak spot and ejector breakage, or material pulling loose at the pivot pin lips of the C allowing the ejector to fall out.
|Remington 740 visible pivot pin hole in receiver||Remington 740 pivoted ejector lays in the LH side|
It seems that they may have wanted the semi-auto to come out first, or at least at or near the same time as the 760 pump. But partial production got ahead of engineering, so they put the 740 project on the back burner, and focused then on getting the 760 out first.
Then when engineering got many of the bugs out, they picked up and finished what guns or receivers were started. Also an educated guess is that part of this problem could have been the gas system, along with that they were probably trying to use the snap in extractor from the then current model 721 (remember the riveted in one was not invented yet, until it came out in the 760). But with this receiver mounted pivoted ejector, it was nearly impossible to make it fit and function reliably in/around the small multi lug locking lugs. So enter the riveted extractor from the 760 and BINGO they could make it function. Once those manufactured pivoted ejector receivers were all used up, they then probably changed over to using the then proven 760 bolt/riveted ejector system and renamed it to model 740A as was common in the industry then. Therefore it is very possible that you will see a 740 milled receiver, but with the later 740A bolt in it as it is unlikely for 740 parts to run out at the exact same time.
In the 740 operation, the bolt lip mounted extractor pulls the fired case out of the chamber, holds it there and as the bolt retracts rearward enough to cam the pivoted ejector inward into a slot in the back side of the bolt body and face, forcing the ejector farther inward into the bolt face farther as it goes back and stops. This then allows the ejector to come in contact with the LH rear side of the fired case, pushing it out from the extractor's grasp and out the ejection port.
Operation of all the later bolt face plunger ejectors (760 and 740A) was similar, except the spring loaded ejector always has pressure on the fired case and as this case is pulled rearward enough to clear the ejection port of the receiver, the force of this ejector overrides the extractor, forcing the case out the ejection port.
As theorized above, the 740 was probably made only during the first year, with the improved 740A coming into the product line as soon as the old inventory was cleared out. This also makes sense by looking at the model numbers, where the 740 would seemingly have been the earliest into the product line / production, followed by the 760, as was earlier production of the models 721 (1948) / 722 (1950) followed this pattern. I have a 740 with serial number 46,965, barrel code PB which was makes it June 1955. I have no basis for this theorization other than looking at it from a engineering / manufacturing / production perspective. You will not see this in print anywhere else, but it about all that makes sense as far as manufacturing.
You will not see any mention of the 740A in any advertising, or stamping on the gun (kind of like the bastard child, it was there but they did not recognize it) and to the general public, no one knows EXCEPT the poor gunsmith that comes on something unexplainable MANY years later (like the plain old 740s).
In the photos below, you can see in the LH photo, the pivoted bar type ejector protruding through the slot in the back side of the bolt head. This is at the rearmost travel of the bolt assembly which is about 3/8" farther rearward than in the RH photo (which is held locked back by the magazine follower). With this bolt at the same location as the RH photo, the ejector does not protrude, which guarantees no cartridge infeeding interference from the magazine. In the RH photo, with pressure on the rear of cartridge of the spring loaded ejector plunger, as soon as the fired case clears the receiver opening, it is thrown clear, up and outward. You will also notice in the RH photo, the angled front of the ejection port cover. This is also designed to give that case clearance on ejection.
|Remington 740 pivoted ejector protruding out the back of the bolt face||Here the Remington 740A & later, plunger ejector mounted in the bolt face|
|Remington 740/740A ejection port showing the metal cover|
Then since the old style ejector soon became obsolete, if a gun was sent back to the factory for this (or any) type of repairs, the repair was to install the new style plunger ejector bolt head assembly. Therefore you may see a 740 receiver with no pivoted ejector but the new bolt head assembly. When I mention "740 receiver" here, I am referring to the visible small drilled hole in the outer LH top of the receiver where the old style ejector pivoted as shown in a photo above. The factory must have also kept a few original 740 barrel assembles, as we have a complete functioning 740 (and so marked) but a barrel dated coded PR which relates to June of 1969. This barrel is a true 740 in that it has the proper rear sight dovetail and Silver soldered on front ramp. It is a true 740 replacement as there are no prior date codes also stamped on it.
I have never seen a 740 in any caliber other than 30-06, but have with the 740A primarily being in 30-06 with a few 308s which would possibly came in late1956. You will find that the 308 did not enter the Remington scene until 1956 when they chambered the 722 for it, so the possibly is great that they also added it to the 740A at the same time. According to the Blue Book of Gun values it does not mention the date of the 308 entered production, just all the calibers available but does say the 244 and 280 coming available from 1957 until this model died in late 1959 (being replaced by the 742).
Now consider the
WINCHESTER was designed by Winchester,
where Remington had an affliction to not chamber for Winchester's calibers
unless it really hurt their checking account. That is also
the reason Remington came out with the 244, to compete with Winchester's 243.
The same for the Remington 280 / Winchester 270. Later said of
Remington "NIH" (Not Invented Here) for many other calibers or industry
standards. Again I am trying to visualize
the whole picture here and from being in the industry shortly after that time (I
got my FFL in Feb. 1959).
I can not remember, or can find in a my reference that the 740s were drilled and tapped for a scope, but I suspect they were as one Remington Forum states about 1954 was the start for D&T in the 760 and 740, which ran parallel to each other, with both using the same initial receiver, with slight modifications as when I bought my model 760 in October of 1954 (date code Nov. 1953) it was not drilled or tapped for either scope, or peep sight. Any D&T that would have been would being tapped for the Weaver #62 scope base and possibly for a peep.
Also there was a 740ADL which was similar to the 740A but had a checkered stock, pistol grip cap and sling swivels. The 740BDL was similar to the ADL but had select wood.
|Remington 740ADL showing some of the checkered wood|
You will notice on the above photo that since the scope is mounted so low, that the original dovetailed rear sight has been replaced with a Lyman folding rear sight, which is common.
One problem with this model 740 firearm was that
the forearm attachment screw was a single pitch thread, pulling the forearm
tight against the front of the receiver. When firing rapidly the 2nd and
3rd shots seemed to always climb, hence making the gun shoot higher with each successive shot.
Williams Gunsight Co. made a aluminum spacer called an Accuracy Block, that went over the forearm screw and
between the metal forearm liner and the gas nozzle block, tightening at the
front and therefore making the forearm float
at the rear.
These forearms are rather thin wood that is glued onto a sheet-metal liner as reinforcement. No factory replacement parts are now available, and very few aftermarket (other than extractors and wood) are available.
The 740 and 740A bolt cover was made of blued sheet metal on these models and was not as prone to rattle as the 760 was because of the bolt handle providing some resistance.
This magazine was designed so that on the last shot being fired, the action remained open. In reality the only reason for this was so you could have the action open for cleaning, as in normal shooting, after the last shot, you now have to push the follower release button on the magazine allowing the bolt to go forward before you push the magazine release button to remove the empty magazine. This can be a hassle for some, so many just use the 760 magazine which is the same without the hold open feature.
Sights have changed many times over the years. If yours is one of the early guns (740) with a 3/8" dovetail, any aftermarket 3/8" sight, both front and rear will fit.
Sights : Don't ask me to ID which sight would have been used on what year a gun, as I am not a Remington historian, just a lowly country gunsmith. However I will try to show photos of most of the different versions. In the LH photo below, you see the original 740 and 760 rear sight. The RH photo shows the first 742 rear sights. These were screwed onto the barrel using 2 screws, the rear blade and flat spring base was held in place by a cross screw in be front part of the base. The fragile rear blade had a windage adjustment screw and used a blade type notched elevator.
|Remington 740/740A/760 original rear sight (G1)||First Remington 742 & corresponding 760 rear sight (G2)|
In the photos below, both of these sight assemblies are again screwed to the barrel (using the same hole spacing as it's predecessor). The base has a male dovetail on the inclined top ramp.
For the LH photo, the upper blade base was secured by a cross screw pinching onto the dovetail. The windage blade was adjusted by the blade having 2 small Vee horizontal grooves, mating into Vee ridges of the blade base and was secured by a center screw buried in the front of the blade. This screw was notorious for loosening and the blade disappearing.
|Remington later rear sight (G3)||Remington late rear sight (G4)|
If your barrel has the sights screwed onto it like the 700 or 742s, you loose part of the rear sight, you might be best to try to get a whole new one for the 7400 or even the 700 series, as the screw holes are all the same spacing. The rear screw on sight has been changed 3 times and parts for the early versions are no longer available from the factory. All screw on front sight bases have the same hole spacing, so any later Remington front sight unit will fit, however the height of the blade may be different if off a different model.
For those of you that have to know what year your Remington firearm was made CLICK HERE to go to the barrel date code.
Model 742 : In December of 1959, the Model 742 was introduced replacing the Model 740A. In January of 1960, the Model 742 was introduced in grades of A, ADL, D and F with caliber's in .257 Roberts, .270 Win, 300 Savage and the BDL versions. January of 1962 brought the new version of the Model 742C and CDL (carbine, 18 1/2" barrel) in .280 Rem, 30-06 and the .308 Win. In January of 1963, the 6MM Rem was added. January of 1964 brought about the discontinuation of the .280 Rem in the CDL grades.
The 150th Anniversary edition, in limited quantities, came about in January of 1966 in BDL grade. This version had a longer flat on the top rear of the receiver with a small flare at the rear, right and left hand stocks in caliber's of .30-06 and .308 Win. This version also had a cheekpiece on the buttstock and basket-weave design for the checkering to differentiate it from the ADL.
January of 1968 brought in the .243 Win and ADL calibers with a change to the checkering on the ADL and C grades, thus eliminating the A and CDL grades. January of 1976 brought about the Bicentennial Edition in limited quantities. The 7MM Express Rem. cartridge was the new designation for the .280 Rem in January of 1980. In December of 1980, the Model 742 was discontinued and replaced by the Model 4 and Model 7400.
Here I suspect the A suffix designation change to mean standard, instead of improved as in the 740A, while the B being deluxe, and there were also D and F suffixes, which designated higher grades yet. And to confuse things, they also added the DL suffix.
|Magazine add of 1960 showing Remington 742 being introduced|
Sights were improved, replacing the dovetailed barrel version with Remington's own screw on rear sight with a sliding dovetail ramp for elevation plus a cross dovetail for windage was implemented. The front ramps were also screwed on.
The buttstocks were made with the
comb a bit higher to be more aligned for the use of a scope. The early 742
wood was not checkered and forearm was the vertical ribbed (corncob style). The buttplate was made of plastic, and
had as seen below, white line plastic spacers at buttplate, pistol grip and forend cap,
but no factory sling swivels.
|A later Remington 742, NOTE the higher comb on the buttstock with white spacers & newer rear sight|
The 742 incorporated a different forearm attachment screw which had a dual pitch thread. When installed correctly, the 2nd pitch threads pulled the forearm slightly away from the front of the receiver, (where one thread screwed into the forend cap and the other at a different pitch into the gas block) creating basically a free floating forearm, making for more accurate shots after the barrel warmed up. When installing these forearms, the screw needs to be partly screwed into the forearm, then pushed rearward until tigfht against the front of the receiver, and then continued tightening, securing it while moving it forward for free floating. This gap between the rear of the forearm and the front of the receiver should be about about .025". If more or less, remove it and either pre-tighten the screw in a bit more or less and try it again until you have about the right clearance.
The 742 has an improved bolt system incorporating a bolt latch system (where the 740 had none), which is a small thin lock that holds the bolt head from rotating out of battery while it is traveling rearward and forward during cycling. However you can not just replace a 740 bolt head with a newer 742 head because when they added the bolt retainer latch in the 742, they had to make another machining cut to the upper inside of the receiver.
In Feb. 1977, date code (LO), on the 742 AND the 760s, the barrel threads were changed from RH to LH, to help stop the problem of the barrel extension (locking lugs) from unscrewing from the barrel during the firing cycle. This date code is shown below in the gunsmithing section.
No factory replacement parts (other than 7400 magazines and magazine latches), and very few aftermarket (other than extractors, firing pins and wood) are available.
The bolt cover was changed from metal to a plastic material on these models which pretty much eliminated the rattle.
Magazines : These steel stamped magazines were a work of art to the sheet metal stamping field at the time they came into existence. They were designed to hold 4 rounds.
Remington did not own the tooling to make the magazines, but a stamping company made the tooling for consideration in making them. These were stamped out and DEEP DRAWN from a single sheet of steel. Over time, the tooling wore out and the tooling company had changed ownership, the new owners were not interested in either rebuilding this old tooling OR making new tooling. I know this, as I tried to purchase the 788 magazine tooling from this company also, but they drug their feet because at that time they were still making the 742/760 magazines for Remington and felt an obligation. Then when the decision came to scrap the 742 tooling, buy the time I found out about it, it had went to the scrap buyer.
The outcome was Remington went to a existing company who was making pistol magazines, who designed cheaper tooling making it differently, with the metal box, but plastic bottom.
Even if you purchased factory spare magazines, sometimes they needed fitting, so they would go in/out easily or locked in place. This could mean usually peening down or filing down the rear latch. Usually the shallow front protrusion was OK.
Magazines for both the 740 and 760 series were all made on the same tooling, so should interchange. The only difference was the 742 utilized a lock open on the last round follower system. They also had a release button on the bottom to override this feature. However it took so much effort that most hunters did not use it, but simply remove the magazine from the gun. It was really a hindrance if you shot the last round and wanted to replace the empty magazine with a loaded one, as you had to first remove the empty one (while under pressure of the recoil spring pushing the bolt unit forward. Not as fast as you would think. The only real need for this feature was when you were cleaning the firearm. With that in mind, many would simply use the 760 as their primary magazine, eliminating all the hassle.
There was at one time aftermarket large capacity magazines
available for these guns, some functioned, some didn't. I have
been asked numerous times by people looking for them, my comment as a hunting
rifle, if you can't hit an animal with 5 rounds, by then the animal would be out
of sight or running so fast you could not hit them anyway.
|Remington 742 BDL post 1966 gun with the stepped receiver & basket weave embossed wood.|
Gunsmithing These Models : Any gunsmithing information listed below will be directed at all versions of this gun unless specified differently, as the 740, 740A, 742 could be categorized as the same gun, just different generations.
These firearms are now obsolete and if you contact Remington, they
will say they don't have any parts. As a matter of fact they don't
even have the part numbers in their parts computer system anymore or if they do
and it also fitting a different model,
the part number has NO reference to fitting these 740/742 models.
To remove the trigger assembly (Fire Control is the actual factory nomenclature), be sure the gun is unloaded, use a long punch, tap out both the 2 cross pins holding this unit in the receiver. These pins are retained by small wired "C" clips once installed. This unit should then come right out the bottom. Now you can manually cock the hammer, with the safety off, try to simulate your problem. You could find something restricting either the trigger from being pulled (safety) or movement of the sear to disengage the hammer.
|Here you see the "Fire Control" assembly removed from the receiver|
If the problem is in the safety, there is a small cross pin in the metal housing above the safety, This pin only holds the spring and either a ball bearing or plunger (depending on vintage). Drive this pin out, carefully remove the spring and plunger. Now the safety itself can be removed. REMEMBER WHICH WAY IT CAME OUT, it will go in wrong but not function. Clean, oil with a light oil (NOT WD-40) blow all the excess off the internal parts, then reinstall.
Trigger pull is usually a little on the upper range and with some creep. This can be improved somewhat by cutting a coil or two off the trigger spring AND very carefully removing a slight amount of metal off hammer notch (maybe up to .010"). HOWEVER be very careful when doing this as all safety/trigger/hammer parts are restricted to factory replacement only, so you can not go, even to a Remington warranty center and purchase these spare parts. Remington has a policy that any spare part that has to do with any possible safety issue if they sold it and was installed incorrectly that they will not sell it -- the gun has to go back to the factory. Therefore any part with the word, Barrel, Safety, Sear, Trigger, Receiver associated with it they will not sell individually.
The first thing I would look at if a feeding problem seems to be the culprit, is
the magazine. Feeding problems on these series of models can many times be
traced to the magazine as with any semi-auto. Here the average
hunter is more likely to leave the magazine loaded even when the gun is put
away. Also the magazines will have been carried in a pocket where
lint, twigs, dirt etc. can accumulate. With this debris internally
the live round can be restricted as it tries to feed up into the chamber,
possibly causing a malfunction. Also they can have became sat on,
squashed so as to not allow the follower to come all the way up. You
notice I do not use the word “Jam”, as it is so broad a term that it is
essentially useless when relating a firearm malfunction.
The followers from these semi-auto magazines will tax your imagination and patience to remove (because of the hold open unit is attached to the follower), then on reassembly again to reconnect them back onto the trip latch. I would suggest that to clean the internal parts of one of these, that either you soak it in solvent, blow it out with compressed air at the same time depressing the follower. Or if you happen to be dumb enough to disassemble one to get it clean, pay close attention to how it came apart as it has to be twisted sideways while holding your breath and jumping on your left foot 3 times.
|Here you see the magazine assembly for these firearms, note the follower release button||Here you have one of the aftermarket high capacity magazines|
The next to look at would be are reloads being used? Reloads are not bad, BUT the reloader needs to be WELL aware of proper case sizing for semi-autos. This is a completely different animal than for bolt action guns. A small base die needs to be used that sizes the WHOLE body back to original factory specs. Also if a crimp is used on the case, it will have to be trimmed accordingly so there is no bulge at the neck. This reloaded case MUST fall into the chamber, as there is very little caming power on the rotating locking lugs as compared to a bolt handle on a bolt action rifle. This is also true with the 760 pump.
Also it is advisable to only reload them to be used for hunting 2 or MAYBE 3 times. As when using the small base resizing die needed to resize back to original dimensions, it will also work the base of the case which can create a case head separation of the brass after a few loadings (squeezing it down, then it being blown out numerous times when being fired). You can reload them more, but use these multi loaded ones for target practice. Paint the primer with nail polish to identify those. Believe me it is rather helpless seeing an animal you just hit, but did not go down, then run off with you holding a useless firearm. You have a case head separation in your gun and about all you can do in the field is to just can stand there with your finger in your nose.
Another thing to look at if you reload is that the pressure
level has to be near the factory otherwise the bolt will not cycle fast enough to
eject. You can not load a light load and expect the rifle to
function. Read the reloading manual and try to pick a load at LEAST in
the mid range.
You guys that say "I have reloaded for 30 years, therefore I know what I am doing" does not mean a thing if all his experience has NOT been for semi-autos pr pumps that the reloader himself is NOT in turn using this ammo themselves. In all may years as a gunsmith, I have seen a considerable number of so called experts come in with blown up guns. Hell, I have been eating food for 80 years, but that does not make me a cook.
To remove the bolt assembly from this firearm first you need to remove the trigger group assembly (as described above), then you have to remove the forearm. Unscrew the front forearm retainer screw, slide the forearm off forward. In the underneath barrel gas port lug there is a sheet-metal U gas nozzle/recoil spring guide that is held in place by a crosswise roll pin. Drive this pin out. Pull the guide rearward enough to clear the gas nozzle on the barrel lug, then the U shaped guide down, then pull out and forward the metal guide tube. Now the recoil spring can be removed from the rear side of the operating rods forward gas block.
Slide the recoil spring rails back enough to disengage the bolt's locking lugs. If you roll the action over and look up into the receiver at the location of the operating handle, you will see the inner end of a small (1/16" diameter retainer pin. This holds the base of the operating handle in. Roll the action over and locate the upper (outer) end of this pin (you might have to slide the ejection port cover a bit to locate the pin). Using a punch, drive this pin INWARD and out of the bolt carrier. Catch this pin as it falls free in the inside. Now the operating handle can be withdrawn outward and out of the gun.
A word of caution here, on these semi-autos, the inner part of the operating handle also doubles as a bolt head cam pin, engaging in a cam slot in the bolt head. There are two cams, one on each side. The cam pin on the far side is simply a short 3/16" diameter pin that can fall out when disassembled as it is simply retained inside when everything is assembled. These pins are what connect the bolt head to the bolt body.
In the front receiver below the barrel where the recoil spring abutted there is a 3/8" threaded stud (you will not see it). This is attached to the front of the receiver and protrudes forward and through the barrel extension, all of which holds the barrel in place by a round threaded nut. On the 740 there are 4 holes drilled around the periphery of this nut that can be accessed by a special wrench. However you may see chisel or punch marks around the outside left by previous repair operations where the wrench was not available. The 742 uses a hex nut, but it is an uncommon size (25/32") and again hard to unscrew because of it's closeness to the barrel and the action bars. The factory made special open end wrenches that had thin outer ends, allowing it to reach in farther on the nut, yet clear the operating rods somewhat.
If this nut gets battered or you wish to upgrade and replace it with a standard 3/4" wrench size, one made for the 7400. Once this nut is removed, remove the thin dual eared spring under the nut. This flat U shaped spring is designed to put tension on the inside rear of the forearm to keep it from rattling. Now the barrel assembly, operating rod and bolt assembly can be drawn forward and out of the receiver.
Shown in the photo below the slide has been held back about 1 1/2" to clarify things by showing the gas nozzle. You can see the front roll pin retaining the U shaped guide retainer, with the gas nozzle between the barrel and the recoil guide. At the complete forward position, this nozzle is enclosed inside a blind hole inside the large metal block that is attached to the action slide arms. Upon firing, the burning gasses expand and rush out the hollow nozzle, pushing the spring loaded block and arms rearward, retracting to extract and eject the fired case. At the end of the stroke, the recoil spring pushes everything back, loading a new round and chambering it ready for another shot. At the rear of the recoil spring (which goes over the guide tube) you can see the hex nut that holds everything together.
|Remington 742 gas system|
In operation on these 742 models, as the bolt moves out of
battery the bolt latch locks the rotating bolt head, keeping it from rotating.
This bolt latch lies in a slot in the bolt body. The front of the latch
has a downward angled front ear that goes into a recess. Directly
behind this front angled recess is a small hole the dia. of the slot.
There is a spring loaded (.087 dia.) pivot pin that goes into this hole with a
spring under it. This pin has one rounded end. This
rounded end goes UP to act as a pivot for the latch. There is also
another hole in the rear of the slot. The pin that goes into this
slot also has a spring under it. But this plunger has BOTH ends
square, as the upper end acts as a retainer against a square matching notch in
the underside of the latch. However sometimes the rear plunger does
not have enough tension to really hold the latch in position during cycling.
|Remington 742 bolt latch #16988|
Remington’s solution was to drop a #7 ½ lead shot pellet into this rear plunger hole before you put the spring in. This increased the tension and improved operation. Many of the 742 parts are now obsolete, this plunger being one, so if you make a new plunger out of .087 dia. drill rod, make it .280 overall length, you will have done the same as installing the lead shot as a spacer under the spring. You may well try the spring and your new plunger in the assembled unit before you install them in the firearm, as if there is any debris in the hole or a slightly short hole, the latch may not be depressed far enough to allow the bolt carrier to depress the latch far enough, so you may have to shorten it. Or if it is one that the factory or a gunsmith who attended one of the last seminars where this tidbit of information was passed on, the hole may be shorter already where it may be hard to get the lead shot out without drilling.
Another problem with these guns is that the chambers tend to get rusty. These extractors are a light metal "C" type clip with a small hole on one end that is used with a rivet to anchor it into the bolt head, and on the other side of this extractor there is a slight protrusion that has a sharp rear edge that acts as the extraction point.
At first the rusty chamber situation may just be the cause of extraction problems. Then since things do not improve by themselves, the extractor may get bent and not be as efficient as it should be.
As things worsen, the gun can malfunction by not pulling the case from the chamber because of the internal rust in the chamber gripping the fired case and or the faulty extractor. If the rusty chamber gets bad enough so the case is really stuck, the bolt will come back with enough force that it can rip the lips of the bolt face off. This then leaves no metal to hold the extractor into the bolt head. You now can have a really stuck fired case and a broken bolt head.
In the pictures below the barrel was almost ruined by
neglect, but was salvageable because it was caught early and was mostly surface
rust. The bore was bad also that when I got the gun, but it was firing
and extracting, much to my dismay. I was able to salvage this gun, by
polishing the chamber with crocus cloth, fire lapping the bore, and the gun is
still in service today as far as I know.
|A 7400 with a rusty chamber||Obviously someone used this one in a rainstorm
& neglected to clean it, look at the rust on the spring guide rod
A GOOD gunsmith/welder can weld the broken lips of the bolt, re-machine it back and reinstall a new extractor. If the chamber rust is not too bad it can be polished out with fine emery cloth wound around a slotted flexible shaft mounted in a 1/4" drill motor. It has been discussed on some message boards to not do this because it will change the headspace. BULL SHIT, and these are not match rifles.
Well, the gun is somewhat ruined now, whatever you do to get it operational makes it better than it was. Sure you may have made a slight change in the chamber diameter, but using this method, you can not remove an excess amount UNLESS you use course emery cloth. Also do not believe any BS you hear about the chamber HAS TO BE slightly rough. Look at any new semi-auto and you will see a very smooth chamber, some are even chrome plated. If it is somewhat rough, the extractor will indeed pull chunks off the case rim leaving the fired case in the chamber OR it will rip the bolt lips off that hold the extractor in place in the bolt. The roughness idea may have come from a retarded blowback pistol, which this is NOT THE CASE HERE.
These later guns (742) use a plastic type ejection port cover, which is now obsolete by Remington, but made by an aftermarket business. The 7400 cover is slightly different, but usable if you alter it to be close to the old 742 cover. The 7400 is a bit longer, but that does not hurt operation, however it is .640 in height. You need to remove .040 off the bottom and alter the front end to close to the 742 shape. You can not get it all the same there, but enough to work. But don't cut it so close on the lower forward end that you weaken it. The other thing, you may have to remove a slight bit from inside the forward slot if the operating handle bumps on the closed stroke. You will notice the operating handle notch is in a different location, but that is inconsequential being only used on disassembly.
|Remington 7400 ejection port cover on top & 742 on the bottom|
After many years of pondering why these guns were plagued
with this rust case phenomena and not the makes or models of others, the following answer
finally came to me one night about 2AM. It was the dedicated, hunt in the cold/rain,
deer/elk hunters that seemed to have the majority of the problems.
The sunshine hunters appear to not have any problems.
In the Pacific Northwest, elk season is later in the year when the weather is nasty, cold, rain, sleet and blowing. Also here the brush, replanted young Douglas fir or Hemlock trees checker boarded between thick timber, so the hunters usually get out in the brush in the morning, get wet and cold, and then drive around on logging roads in the afternoon to dry out, in hopes of see animals that some other hunters have put on the move. In the state of Washington, a loaded firearm in the vehicle is illegal, so they unload the gun, remove the magazine, rest the muzzle on the floor possibly between the 2 hunters or in a gun rack for quick access.
This could also happen in a very humid climate.
But here in the colder weather if the gun is brought into a warm vehicle, the barrel will condense water on the inside, since the
action is spring loaded and has no means of being held open without an empty
magazine inserted, so the average owner simply leaves it closed. The
gun has gotten wet and COLD, now it is subject to a forced HOT air from the
heater, in this close proximity to heat, the COLD steel condenses moisture on
both sides of the steel. With the bolt forward under spring
pressure, with the muzzle down, when the barrel warms up the inside has
condensation, this rises, and is trapped inside the chamber. And now this moisture inside has no place
to go because the bolt is closed.
If the drive home is long enough and/or the firearm stays there long enough, the outside condensation will dry off. And at the end of the day, the hunter then takes it home, may stand it in the corner to dry off. The condensed water inside of the barrel, then runs down, collects in the chamber area. Then possibly the gun MAY see an oily cleaning patch run thru the bore but the chamber is usually missed because it is missed by the patch and also out of sight since there is no way to clean the bore from the rear. This is not an area that the average hunter will even see if he runs a cleaning rag thru the barrel. Usually the bolts are closed on most firearms when being stored. This also traps any moisture inside the chamber. The gun is set away with the bolt closed until the next year with the owner thinking that they have done the right thing. Then the first day of deer season, the gun gets shot, but it will not cycle the 2nd round because the fired case is stuck in the barrel. The end result is a RUSTY chamber that we gunsmiths have seen MANY, MANY times, but did not understand what may have happened.
At one time the factory supplied a
Nylon chamber brush with each new gun, this brush had the handle made in a "dog
leg", somewhere along the line, non-wisdom prevailed and it vanished out of the
shipping boxes. This brush may have helped in the above situation.
One of the most common problems with the Remington 740 and 742 is that after much use, the receiver rails will get worn. The top receiver rail guides the bolt lugs on the movement both rearward and forward. The receiver is made of a soft easily machined steel since the bolt lugs engage the rear of the hardened barrel extension for a positive lockup. In essence the receiver simply holds the parts together and could possibly be made of aluminum.
This movement is under gas pressure on the rearward movement and spring pressure on the forward movement. At the rearward stop position the inertia of this bolt lug exerts extra pressure, caming it against the receiver rail slot, pounding them enough that this rail gets worn. There is a bolt latch on the 742 (this latch was not on the 740). This latch is supposed to lock the bolt head into the bolt carrier to help keep the front from over-rotating at the most rearward inertia's movement, but after enough wear on all parts, things seem to get sloppy and do not really function as intended.
When this happens the bolt lugs, now slightly out of time/position, having been moving back and forth of the force of the gas system, may also chew up the front of the rails. Then this happens the bolt carrier and lugs can get bound up, then in extreme circumstances actually stop the bolt unit from cycling when the gun is fired, or binding it on the return stroke enough to stop it before it completely closes.
Under some circumstances the operating handle may drag, usually on the bottom of the receiver slot that the handle operates in. If this happens it is usually related to the above rail problem.
In the photo below, look at the rear scope mount hole (LH one). Directly below this hole you can see 5 regularly shaped bumps in the guide rail slot, these are caused by rearward inertia of the bolt's 5 locking lugs when they come to an abrupt stop at the rearward end of the stroke of the whole operating system inside the forearm and receiver. Over time, it just keeps being battered more and more to where it can become so bad that the slide unit may become bound up rearward. There is another spot here that is worn but hard to see in this photo, that is again in this guide rail slot, below the front (RH) screw hole and almost to the 2nd hole. This is also caused by the bolt lugs, but not to the same degree of damage, and more of a scraping situation which is caused at the initial unlock stage of the locking lugs.
|Remington 742 chewed up receiver rails|
Since there are no new receivers available and the only used ones could be questionable in that may possibly be worn also, A GOOD gunsmith/welder/machinist familiar with firearms can usually salvage the receiver by welding the worn rails with a long nozzled wire feed welder. This receiver can then be re-machined to factory or even tighter dimensions using a vertical mill and using special long shanked cutters. This is not a job for the average Red Neck "gunsmith", or "welder" however.
In the 7400 series rifles, this problem was eliminated by machining out a wider/shallow dovetail in the inside upper part of the receiver and inserting a hardened steel insert to guide the bolt lugs better. They also changed the small multiple locking lugs on the bolt to less and larger lugs.
If you as a gunsmith have to take the barrel extension off to do any rechambering or rebarreling you will need to make a barrel extension wrench. This extension is actually the barrel's locking lugs. It is threaded and timed to the barrel so that the extension is indexed so the sights, and the barrel lug are all indexed for bolt lockup, and correct headspace so everything where it should be. There is not any commercially available fixtures available to remove these extensions. If you try to use any other method, you will about 99% be assured of breaking the hardened extension. However shown below is a photo of the one I made.
You have all the dimensions you need to make these right in front of you, the OD of the lug extension is the hole diameter. The working end of the slider fits the top locking lugs. The 3/8" hole for the bolt is the hole that the receiver retaining bolt is located in the barrel lug. This bolt does not go all the way through into the barrel lug on disassembly, but is needed in that location for reassembly for re-alignment. The main tool body is .875 thick with the lug engagement slider .500.
|Remington barrel extension removal tool|
In the above photo, the inner slider is made to fit inside the barrel locking lugs. The 3/8" bolt locks the slider to the base. The bolt hole is also aligned with the barrel lug attachment bolt hole. In use, for removal the base is inserted over the barrel lug extension, the slider is then slid endwise into the lug recess. The 3/8" bolt is inserted in just far enough to lock these 2 parts together, but not into the main barrel lug for removal. Mark the relationship of the barrel to the barrel lug with a scribe mark on layout die. This will allow you to reinstall it in the same position. Sometimes these lug units are seized on rather tight. And then the barrel lug can also be tight after you get the lug extension off.
Now Remington changed the threads at barrel date code
from RH to LH to
facilitate the extension not being backed off when used on the semi-auto guns.
This will determine which direction, when you try to remove it from from the
can now put the barrel in a barrel vise, rap the removal handle sharply with a
3# hammer, in the proper
direction, then unscrew the extension off the barrel. These extensions are usually on
tight and require force to remove even after the initial bond is broken.
Once it is off, if the barrel lug is stubborn and resists, you may screw the
extension back on part way, do it over again but with the 3/8" bolt thru the
barrel lug to take both off at the same time.
The picture below of a fired 30-06
Winchester factory round that was fired in a early 742, barrel code (CM) that
the RH threaded barrel extension had became loose, unthreading as the case was being extracted.
On this gun the extractor held the loaded round tight enough to allow the firing
pin to actually fire the round. As luck would have it, the bullet exited the barrel
while the case was still somewhat in the chamber during extraction. You may notice a slight
crease in the body behind the shoulder where this case upon being ejected was
dented as it was going out and hit the ejection port of the receiver.
|Comparison of a normal round & the lengthened case because of a loose barrel thread|
Remington has also discontinued making extractors for these guns (apparently because they are now obsolete by their standards), extractor #14669 which was 30-06 size riveted type and are the same that had been used on the 700, 740, 742, 760, 788 (all obsolete guns). These extractors are riveted into the bolt, require a special rivet and tool to install. The rivet tool and replacement extractors are currently available from Brownells in Iowa 1-800-471-0015.
Bolt latches are also factory discontinued, but are being
currently made by Wisner's Inc. Bolt heads are non existent, except from
cannibalized guns, but by the time a gun has enough worn parts to warrant
cannibalization, they too are usually worn or broken.
Magazine latches are also obsolete. However the larger latch off the newer 7400 series can be used if the new spring is also used.
Firing pins also are obsolete, however I think Pennsylvania Gun Parts is having them made. Aftermarket manufacturers like Uncle Mikes make sling swivel kits to fit these guns.
Buttstock wood is the SAME AND INTERCHANGEABLE for all of the Models 740, 742, #4, #6, 74, 7400, 7600. The factory will not tell you this, but they WILL all interchange. The finish or checkering will not match your original one however. But at this stage of the game, you will more than likely have to take what you can find.
Forearms are a different matter. All 740, 742 forearms are now obsolete, HOWEVER if you replace the complete forearm, front metal plate, spacer, and the screw, then the current 7400 will fit.
The sights have changed many times over the years. The early guns (740 and 760s) used a distinctive rear sight attached with a 3/8" dovetail, where any aftermarket 3/8" sight, both front and rear will fit. Later the factory utilized the same sights for all their center-fire rifles (except the model 600 and 788s), meaning the 700, 742, 760 all used the same sight bases (maybe a higher or lower front sight depending on the caliber). If your barrel has the sights screwed onto it like the 700s, and you loose part of the rear sight, you might be best to try to get a whole new one for the 700 or 7400/7600 series, as the screw holes are all the same spacing. The rear screw on sight unit has been changed 3 times and parts for the earlier two versions are no longer available from the factory. The front ramp was initially silver soldered onto the barrel, later it was screwed on using two screws with one under the blade's dovetail.
About all the newer type pump and semi-auto guns, whether they be rim-fire, center-fire or
shotgun use many of the same basic “Fire Control” parts (as Remington calls the trigger
group) parts. This would be the 552, 572, for the RF, 740, 742, 760, 4, 6,
74, 76, 7400 and 7600 for the CF. 11-48, Sportsman 48, 870, 58, 878, 1100, and the
11-87 in the shotguns. They are now only supplied in Right Hand from the
factory. AND you CAN NOT simply reverse the RH to make it function as a LH
For many years there were aftermarket Left Hand replacement triggers available from sources like Williams Gunsight Co., Uncle Mikes, Herters, etc. However for some reason these companies dropped production. The guess is that if THEY sold you a replacement safety and YOU installed it improperly, that they were responsible legally because THEY SHOULD HAVE KNOWN that someone could also have done something else wrong inside the “Fire Control” unit at the same time, creating a unsafe situation These companies also could have felt threatened by lawyers to the effect that they were making a product that altered the factory design.
You might find some enterprising machine shop that may possibly be making some
LH safeties, but in all probability they too, would not be advertising it to any
degree, because of the possible liability involved.
Early on, Remington supplied some of the trigger guard units drilled with 2
different safety plunger detent holes so that YOU could simply interchange the
RH to LH. They even supplied a detailed drawing of this
placement of the hole so gunsmiths could do it. However they later found
that beings as how this trigger guard was
made of an aluminum casting, that
over time the THIN web between these 2 holes was prone to breaking, then the
safety would not function as designed. More liability, so this whole
idea was apparently abandoned.
Failure to eject after a scope was mounted is a situation that can also be encountered. The usual problem here is that the scope base mounting screws may be too long, protruding down into the receiver bolt rails, and then dragging on the bolt lugs upon firing.
The factory has no current cross-reference to the 742 parts
interchangeability, if a gunsmith orders the 742 part number, the order will
come back saying -- discontinued--. This is very hard to understand
in this computer day and age, but the factory service department underwent a total
restructuring, when they moved to the southern US. The old people who knew
anything were let go, or retired, so the new people either do not know any
history/interchangeability, or were told to not
offer information that some of the new parts will fit. It is
the belief that the factory does not want 740 and 742's repaired, therefore the
above information seems to be more valid. They want you to by a new
model. The factory even can not cross-reference the buttstock bolts,
saying the older ones are obsolete. But the current 870, 7400/7600 stock bolts are
the same and will
There was a factory upgrade for the
worn receiver rails at one
time, where you sent your non-repairable 740 or 742 back to the factory, that
they would exchange it for a new 7400 for the wholesale price. This
however was more than the original gun was worth even in excellent shape.
This program has been
discontinued since about the mid 1980s.
For Remington factory date codes CLICK HERE
It seems that old guns are like many of us, in that just don't know when to give up. Sometimes however it is better to just let the old gun die, but how many of you cherish Grandpas rifle?
Model 4 / 7400 : There may have been some confusion with the other Remington #4, which was a Rolling Block single shot rimfire rifle that Remington made from 1890 to 1933.
This model (along with the 7600) had
internal changes trying to improve the 740/742s. As mentioned above
the factory eliminated the soft receiver problem by machining out a shallow
dovetail in the inside upper part of the receiver and inserting a hardened steel
insert. They also changed the small multiple locking lugs on the
bolt to less and larger lugs. The scope mount location holes were
different and went to the larger 8-40 threads normally used (6-48), requiring a
different scope base. The magazine release was made larger.
When Remington dropped the 742 in 1981, they came out in 1982 with the newer internal design semi-auto, while still maintaining the same exterior configuration. It was designated model 4, and the model 7400. The calibers available were 6mm Rem. (discontinued in 1987) 243, 270, 280, 30-06, 308, and 35 Whelen. A carbine in 30-06 was introduced in 1988. The extractor was changed from the riveted in style, common with the 740, 742 and the bolt action 700 to a non-riveted snap in type. This new style extractor was also incorporated into the model 700 bolt action gun. But the 4/7400 utilized the same, but a slightly heavier/stronger version extractor than the bolt action guns.
The model 4 was the deluxe version (or as the earlier 742 was
designated, it would have been equal to a BDL grade). The model 4
had high gloss checkered walnut wood with white line spacers under the
buttplate, grip cap and forearm tip. The model 7400 which was the same
gun, except plainer wood, satin finish, pressed checkering (would have been
equivalent to the ADL).
In the spring of 1982 at the NRA convention Remington invited us retail dealers to a conference room meeting. The Remington factory sales reps told us (independent dealers) that "they" were advertising for the independent dealer AND promoting the model 4 in all national sports magazines TO HELP US sell their guns. They did not tell us that there was also being made an economy model, the 7400. We found out later in the early fall after we got our shipment of model 4s, that Remington had promoted and sold the 7400s to K-Mart, Wal-Mart etc. at a greatly reduced price as compared to the Model 4 that they were selling us.
The retail customer was not dumb,
as he could buy a new Remington semi-automatic 30-06 from the "marts" for $100
less than we were charging, he did not care what it looked like, only the price, and was very
we could not match their (the Marts) discounted price for our higher grade guns.
The situation was that part of the deal was the "marts" ordered only the 30-06 calibers,
customer could not understand why we could not sell them a 270 Winchester
caliber for the
same price the marts wanted for their 30-06. The end result was that
we were therefore stuck
with higher priced guns on our shelves, and upset some customers.
Then in 1983 Remington acknowledged and then indeed have the 7400s in their sales catalog. The independent shop owners had to then buy the model 7400's to stay even somewhat competitive. So the model 4's sat on our shelves and at the factory warehouse. It took the factory a few years to figure out that what was going on was of their own creation but never admitted it to us.
As time went on, new versions appeared including synthetic
stocked models with glass-beaded dull metal finish, even a Electoless nickel
finish on the metal.
Model 74 : Then later, about 1985 there was an even cheaper model, the Model 74, again made in 30-06 only, which took the place of the then "older" 7400, but with cheaper walnut stained birch wood, with no checkering. The metal finish did not have the higher luster of the 7400. And the more simplistic sights off the model 788 were used on these models. Now the "marts" could again under-price us because we again did not know about these 74s. These guns also carried Remington's economy name of "Sportsman".
In 1987 Remington then phased out the model 4, then soon, the Model 7400 started showing up with the better wood previously found on the Model 4. So in essence the two above guns (model 4 and 7400) in the end were the same except the wood and period of manufacture.
Magazines for the 740, 742, model 4, 7400, 74 are all the same and are interchangeable.
The models 4, 74, 7400 (along with the
6, 76, 7600) were designed with 3 larger locking
lugs, a slightly cone shaped barrel breech for better feeding, a hardened rail
insert in the top of the receiver to guide the upper locking lug, eliminating
the possibility of the receiver rails being ruined. The scope base
mounting holes were changed and increased in size from the normal 6-48 to 8-40
size. The firing pin was redesigned with a gas shield. The trigger group
remained basically the same with the exception of a larger magazine release
About 2002 the magazine tooling wore out and there was only
one company that was able, or wanted to do the deep drawing required for this
operation. As mentioned above this company made and owned the tooling under the
original contract, but when it wore out, they opted not to continue making the magazines for
Remington then had MecGar make new replacement magazines out of 2 pieces with
the bottom of nylon attached to the sides instead of a single drawn magazine.
However the new magazines may require fitting to the older guns.
Model 750 :
The year 2006 saw the Model 750 replacing the wood-stocked Model 7400 versions
and features a restyled American walnut fore-end and stock with machine-cut
checkering. And was
also available in a brushed stainless type finish. It later came out with
a black synthetic stock. It comes supplied with factory sling swivel
The factory advertisement says felt recoil is diminished by its ultra-efficient gas action (what ever that is) and the addition of a revolutionary R3® recoil pad. It is supposed to have a better self-compensating gas system. My guess was that they changed the gas nozzle shape so that it dissipates the gasses better as the action bars move the attached gas block rearward. And/or they possibly just chrome plated parts of the 7400 gas system and are calling it improved.
However I recently received some further information from a person who had gotten info direct from Remington "The model 750 uses a different gas block system. The 74 series of rifles used a 90 degree gas port system. The model 750 uses an angled system inside the gas block. "
OK, I'm close, as this could result in a slightly different cyclic rate using a different gas bleed off method.
This model appears to me to be a regeneration of the earlier Model 4 as a deluxe
model with a more beaver-tailed forearm which also provides more wood around the
inner sheet steel liner, which will also improve the cracked forearm issue.
|Remington model 750|
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LeeRoy Wisner All Rights Reserved
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Originated 10-17-06 Last updated 01-17-2017
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