Winchester model 88 & 100 
Information

 

 

 FIREARMS INFORMATION

 

 

I won't go into a lot of detailed collector history of these models here, only gunsmith type information, other than the 1st  3  paragraphs.

The model 88 rifles with 22" barrels were made from 1955 to 1973 with about 284, 000 total of all versions being made.   This model was made in 308 Win. caliber the first year, with the 243 Win. coming in 1956.   It is not sure exactly when the 284 came into being, but it apparently did not come out  until about 1962.   The 358 was made only from 1956 to 1962.  The 19" carbine from 1968 to 1973.   The carbines utilized a front barrel band that the sling swivel was attached into.    The carbine stock was actually a little longer at the forearm than the standard model, apparently to provide for the barrel band not ending close to the end of the wood, creating a cosmetic imbalance.

The model 100 rifles with 22" barrels were made from 1961 to 1973.  The carbine with 19" barrels were made from 1967 to 1973.  A total of 262,000 being made for both versions.   This model was made in 243 Win, 308 Win and 284 Win. calibers only. 

Stocks were checkered prior to 1964, after that they were impressed in a basket weave pattern. 

Most of what I will cover are some bits of information as to differences and common problems encountered.  Many of the internal changes in these guns were related to introducing new calibers, and modifications related to that.  The magazine was a headache from the start, so many changes were related to solving problems related to it and feeding.  Then when the model 100 came out in 1961, improvements incorporated in it were also transferred on to the model 88.

Serial Number Letters : Prior to 1968 no serial number prefix was used.   As the result of the Gun Control Act of 1968, Winchester assigned letter prefixes to the serial numbers to designate most models, the letter "H" was assigned to the model 88s while "A" was used as a suffix to the model 100 serial numbers.    You may see a suffix to a serial number of "A" on a few earlier guns.  This appears to be possibly a duplicate or more likely a replaced receiver/barrel unit.

Winchester Model 88 serial numbers
Year S/N Year S/N Year S/N
1955 1 - 18,378 1956 36,756 1957 55,134
1958 73,512 1959 91,590 1960 110,268
1961 128,651 1962 169,838 1963 148,858
1964 160,307 1965 162,699 1966 192,595
1967 212,416 1968 230,199 1969 H239,599
1970 H258,229 1971 H266,784 1972 H279,014
1973 H283,718        

 

Winchester Model 100 serial numbers
Year S/N Year S/N Year S/N
1961 1 - 32,189 1962 60,706 1963 78,863
1964 92,016 1965 135,388 1966 145,239
1967 209,498 1968 210,053 1969 A210,999
1970 A229,995 1971 A242,999 1972 A258,001
1973 A262,833        



Receivers
: There were at least 3 changes inside the receiver that we are aware of.   First year of production saw 2 machined lips for the front top of the magazine to rest on when it was locked into place.  The rear set was approximately at the location of the shoulder detent of the magazine.  Later receivers had this rear lip machined out.  It is suspected that this came about in 1956 somewhere near s/n 25,000 when the 358 came into being, as this rear lip would have protruded inward so far that it would interfere with feeding of the necks of the 358 cartridge.   Also we have found on later guns at a serial number of near where the 284 was introduced that the front lips was moved forward slightly.  In the pictures below the feed rails were sandblasted to show better details.

early receiver 308 cuts receiver cuts to accommodate 358 receiver cuts to accommodate 284


The model 88 receivers underwent numerous changes during the production span.  The front receiver ring was changed in length of the ejection port opening, with the supposition of it to accommodate the ejection of the 284 for the model 100.   Since the new longer ejection port works for one model and caliber, they simply made all of the receivers the same in this aspect.   The older receiver had a front length at the recoil lug area of 1.125", later then probably near s/n 115,000 this was moved forward to a dimension of .875" making a 1/4" longer ejection port.  A quick glance will allow you to see part of the top locking lug on the later gun. 
 

Early front receiver ring Late front receiver ring


Also the receivers made before the introduction of the model 100 have a bolt sleeve lock pin that rides in a longitudinal groove in the LH inside of the receiver.  At the forward end of this slot is a milled out section in the side and up into the top of the receiver to accommodate this pin as it rotates on the locking lugs engaging the receiver lugs.   This pin and the bolt sleeve rotate which then allows the firing pin to become unblocked at the rear, letting the gun fire.

This photo shows the slot & recess for the early sleeve lock pin clearance


On the early 88s as shown in the photo below on the left, there is a slot milled into the LH side of the receiver to accept the sleeve lock pin.  After the model 100 coming into being, the bolt sleeve was changed on the model 88 which now uses the newer 100 firing pin system.  In the photo on the right you can see the shallow cut in the top of the bolt sleeve, there is a mating protrusion milled into the top of the receiver which now acts as a guide for the bolt sleeve.

Early bolt sleeve & firing pin Late bolt sleeve & firing pin


Extractors :
The model 88 used three different extractors, the early guns use #1288 that used a “tee” style guide slot.  The model 100 came into being in 1961 at S/N 110,000 for the 88.    The 88 and 100 then utilized the same extractors, #1200.  Then at s/n 178,000 the final #6300 extractor, utilizing a dovetail slot, was used again for both models.

Ejectors : The early 88s had a single large ejector, later changing to the same as the small dual ones used on the model 100. 

Firing Pins : At about the time the model 100 came into being, the 88 underwent internal changes in that many of the 100 parts could be utilized.  One of these was the firing pin.  Even the replacement recall firing pins will fit the later model 88’s. 

Finger lever : Notes taken from a tag on replaced sample parts from a warranty center from that time frame indicate.  "Old Style #1988 Finger Lever - This lever had an adjustable stop screw which was done away with.   Also the projection on the top front is about 1/8" longer than on the new style. The New Style lever will not trip the guard latch on the O/S rifle. maybe a new guard latch will solve the problem."  In reference to another gun, "serial number near 85,000 still has short trip tang on finger lever, but does not have the stop screw"

Hammer Catch :  Also on another sample part's tag. "Sample #3988 Hammer Catch - The New Style has a longer tail. this longer tail holds the hammer down farther when cocking rifle, keeping it from dragging on the bolt. Rifle works smoother."

Recoil Block : Rifles under s/n 82,900 (or about mid year 1959) had a cloverleaf recoil block, later ones were a larger rounded style.   Part number changed from #6988 to #6988B.  The reason for the change was that the inletting of this block into the stock at the rear was prone to crack the stock under recoil.  The new block style sat on top of a stock shelf which solved this problem. 

Early clover-leaf type recoil block on Left with the later on the Right



You may see some older guns
with a new style recoil block and a replacement stock.   This is because when the inventory of factory old stocks was gone, the factory ad warranty centers used new style stocks, but then had to also use a new style recoil block.

Replacement Barrels : The model 88 and 100s were never offered any replacement barrels, even from the factory.   These guns had the barrels screwed into the receiver, headspaced, and for the model 100 the gas piston base was silver-soldered onto the barrel and then the caliber with the rollmarking placed on the barrel before it was blued.  For the factory to replace the barrel, the receiver also had to be replaced as a unit.

Unlike most other guns, the headspace in either the model 88 or 100, is not necessarily determined by whether or not the action appears to close over a minimum (Go) or maximum (No Go) headspace gage.  Rather the significant factor relates to the rotation of the bolt head when viewed through the magazine well.  To check headspace, proceed as follows:   First, close the bolt on an empty chamber and note the position of the bolt in relation to the locking cut.  Then apply a light pressure on the locking lug, using a screwdriver or something similar, and the bolt will rotate farther.  Now, with a minimum headspace gage in the chamber, the bolt should rotate to the same position as it did with the chamber empty, unless the headspace is below the minimum.  If additional rotation is obtained with light pressure applied against the locking lug, it is an indication that headspace exceeds the minimum, which it should.  With a maximum headspace gage in the chamber, and no additional rotation should occur even when pressure is applied to the lug.  In the event that additional rotation does take place, then headspace is excessive.

358 Sales Slow :
Apparently the Winchester factory
played it low key when the 358 was introduced,  probably because of the feeding problems encountered.   At the time, the 348 was a favorite with larger game timber type hunters, but since the 358 was a smaller case, without factory fanfare and outdoor writers praising the 358 being able to do what the 348 could do but in a lighter gun, the 358 did not initially sell well.

One well known Portland Oregon gunsmith that was Winchester factory warranty at the time, remembers that many of the wholesalers were stuck with an abundance of unsold model 88s in 358 caliber on their shelves.   Winchester allowed them to return these 358s to be rebarreled to either the 243 or 308.   Therefore the actual number of 358s produced may be even less than any factory records may show.


Feeding : Feeding will always be an issue on any firearm, this was no different from the start for the model 88, or the model 100.  However lead the following section below.


Model 88 Erratic Feeding :  Sometimes the model 88 will not always feed the nose of the cartridge properly.  If nothing else can be found that can contribute to this failure, look at the speed of the lever cycling. This gun needs to be operated rather abruptly, as close to the model 100 gas operation as possible to allow the ammo to feed right.   Also, at this same time the gun has to be held either at right angles (right and left) to the ground or tipped to the right if anything.  DO NOT TIP IT TO THE LEFT so you can see what is happening.  If it is tipped left and and at the same time fed slowly, the ammo feeding can be erratic depending on which side of the magazine the cartridge is fed off from.

When trying to track down feeding problems, look first for cleanliness, remove all the grit, rust etc. from the inside of the magazine.   The box may have over time become spread outward in the middle (front of the feed lips), place the box upside down in a vise and slightly squeeze it inward so that the middle sides are equal to the end dimensions.   Also as a last resort, you might want to bend the front of the lips up SLIGHTLY, being careful to correlate this with the bullet feeding into the chamber. 

Cleanliness is important with all firearms and more importantly with semi-autos.   The model 100 being no exception here.  The early gas pistons were ordinary steel, with later ones being made of stainless steel.   These guns need to be disassembled and the gas system cleaned a each season.  If not, the piston can rust enough to bind into the cylinder, it is then about impossible to take the gun apart. 

 

Magazines : There are 4 basic magazine designs.  Initially they designed and made the model 88 rifle, but it took almost a year before they had a good design for the magazine and before they actually shipped any guns.  Even these early guns had a different magazine than came along later.   We will call it type 1 which would probably have only being made during the 1st year.  There was an intermediate design (type 2) that no one is sure of when it was ended, with the type 3 being brought in shortly thereafter.  Then it appears that the final one (type 4) came into being somewhere between s/n 14,000 to s/n 20,000 being a realistic number.  

The model 88s were made in 243, 308, 284 and 358 Winchester calibers.  The 243 and 308 use the same magazine.  The 358 used the same basic 243/308 magazine except it was altered to feed the wider necked 358 cartridge.   The few 358 magazines we have seen have no caliber marking, and apparently were made utilizing the type 1 magazine box.  

 

Magazines for the model 88 first year of production had no caliber stamping apparently because at that time the gun was only made in 308 caliber so they saw no need to designate differently.  The front of the boxes had a radius cut out on the top to conform to the chamber of the forearm.  The rear top upper part which forms the feed lips is straight from the front to the rear.  

Early followers were a stainless steel stamping.  The had what appears to chemically etched on the top LH flat "4ctgs,oly".   Later followers did not have this etching with the flat being changed to a radius to from a nest to cradle the LH cartridge case.   The follower springs were only held into the followers by the top front being slid into a pocket in the front bottom side of the follower, this attachment could lead to the spring moving to the rear, changing the pressure pivot point.

In reconstructing the possible manufacturing/functioning problems of these early magazines, we have concluded.  

The assembly of the bottoms to the sides went thru a progression by having the bottom lips attached to the sides by different methods.

(1) The type 1 are identified by the top of the stainless steel followers etched with "4 ctgs,oly" on the flat of the LH side.     The boxes were attached to the bottoms, utilized a punch mark at the location of the shoulder dimple area since this shoulder went all the way to the bottom so when the box was formed with the bottom lips that were to retain the bottoms there was no material there on this lip, so it was the location for the retention divots.

 

 

Type 1  Stainless Steel model 88 Follower


These old magazines were described as the “flat bottomed” magazines.   Being made of softer material, with the cartridge shoulder dimple running all the way into the bottom, as shown in the LH photo below, making the box weaker.   Also the follower spring not being secured to the flat wide bottom could get shifted sideways creating problems with the follower binding. 

On the RH photo below you will notice a deeper bottom and radiused notches in the feed lips.  The later magazine on the right is stronger because of the shoulder rib does not terminate at the bottom.  And with the newer narrower "pocket" to secure the spring from shifting improved functioning.

The early type 1, 2 & 3 magazine boxes The type 4 magazine boxes


(2) Type 2 are identified by still using a stainless steel follower, but instead of a flat on the top, a radiused groove was put there instead to form a nest for the cartridge that laid on that shelf.  The 2nd retention system was by simply having the front bottom corners being squashed flat onto the box bottom lips, pinching the bottoms on.  Apparently that method was eliminated because the bottoms may have been able to slide off the boxes during usage.


Type 1, 2 & 3  Stainless Steel 88 on left, Type 4 cast 88 center & 100 on right


(3) Type 3 still retained the stainless follower of the previous version.  This method of securing the sides to the bottom was to stamp a front and rear radius detent that was just at the outside front and rear of the box bottom.  The front detent was deeper than the rear because it could protrude down into the hole in the area where the magazine latch was installed.  The rear where the box's bottom lip nestled was flat across and appears to be a very close tolerance fit.  Now let us guess that the assembler of these boxes may have not been fully wide awake at times and could have placed the boxes into the riveting/detent squashing die with the front not toward the front all the time.  This could have made the deeper detent on the rear, with minimal clearance for it the right way, this mis-detented magazine will not stay in the firearm securely upon firing.

Also it appears that the original magazine latch may have been slightly short allowing the magazine some sloppiness on the front when locked into the receiver.  This could have been on purpose initially to ensure that the magazine would lock in place no matter what tolerance was compounded by all components.  This however could have also contributed to feeding problems in that the front of the box really governs where the bullet noses are directed into the chamber.


Model 88 followers showing side view


(4) Type 4.  Finally the magazine box was extended downward about the thickness of the material or .040.  This was apparently needed to compensate for the new deeper cast aluminum followers.  The bottom attachment was changed again to a combination of both the front corners, the front and rear detents.  The difference in the front 4 corners this time was that this time the metal was squashed deeper over the ends of the box corners, making it considerably more secure.

At this same time it appears the magazine latch was lengthened somewhere between s/n 14,000 to s/n 20,000 to secure the front of the magazine tighter against the internal shoulder inside the receiver that functions as a upper magazine stop.  There appear to be no changes in how the rear of the box was retained.

On these new boxes, there is a scalloped type radiused notch on top and on each side of the feed lips.  This is to accommodate inserting the new type aluminum followers (which have the spring riveted to) into the box with the bottom pre-assembled onto it.  The caliber was stamped on the upper front of the boxes and had dual calibers 243/308 stamped there.  When the dual caliber was stamped on the box, the front radius cut out was changed to flat, possibly to give enough room to stamp the dual caliber markings.

Bottoms were changed to adding a deeper narrower recess that formed a pocket positioning the follower spring from being able to side sideways.  The arrow pointing forward was made smaller to be able to fit on this new bottom.  The Winchester name was retained on the bottom.

Followers were changed to a cast aluminum material and the firearm model was cast into the front of the follower.  The follower spring was riveted onto the front of the follower.  The only difference between the model 88 & 100 magazines is that the 88 has a sloping rear on the follower while the 100 has a flat at the rear.  This flat is to hold the semi-auto action open for inspection/cleaning.  It also holds the action open on the last shot, making for awkward manipulation of holding the action handle back in order to remove an empty magazine.  Many knowledgeable hunters prefer to use the 88 magazines in the model 100 when hunting because of this.


243 / 308 / 358 follower spring


We can not find out exactly, but the rumor was that these early guns were recalled for a magazine replacement and the magazine latch was also replaced.

So, IF you have one of these older guns and you try to use a newer type 4 magazine, you may have to replace the magazine latch with the newer longer style to facilitate proper feeding.  Type 4 magazine is what the majority of the guns were factory fitted with. 

ALL THE magazines are designed to only hold 4 rounds for the 243/308/358 while the 284 will only hold 3 rounds.  DO NOT FORCE any more rounds in them as that will bend the box and damage it for any later correct feeding.

The later magazine boxes and bottoms used in the model 88 in 243 and 308 are the same as the model 100 as by the time all the improvements were done for the model 88, the model 100 arrived on the scene in 1961.  The model 88  284 has the feed lips moved back slightly and then the model 100 has them set back even farther.   This appears to be because the gun is cycling so fast because of the gas operation, that the next round has to be fed up earlier for reliable feeding.   These alterations to the original factory boxes of model 100 in 284 caliber were done even after the magazines were blued.


358 Magazines :  The model 88 in 358 caliber has a reputation to be fussy in feeding, this is possibly because the heavy bullets of this caliber appear to not function reliably all the time if the operator hesitates ever so slightly in operating the lever. 


Rumor is that the factory used a special fixture, to slightly alter the 308 boxes after they were assembled, however there is no verification of this in all of our factory communications or blueprints.  In talking with the vendor who made them, we can not collaborate this bit of information, but it would have been an in-house operation by Winchester, and the vender would not be aware of this.   And talking to the factory service manager when we purchased this tooling there was no mention of extra in-house tooling, but he was a relative newcomer there.   Now, in retrospect, I suspect there may have been, but even at that time there was probably no one left working there or who could be identified that could verify it.  One second hand source said that he had talked to a retired worker who said there was.


What we have found by closely examining a  358 magazine AND a rifle is as described below.  The above rumor may well be true.  The 358 magazine boxes were apparently modified 308 boxes of the original type 1 boxes, after they were blued and the bottom assembled because I can see file marks on the upper lips that are not blued.  This modification includes the removal of the shoulder detent groves, apparently by inserting the blued magazine box over a mandrel and crimped on bottom (with the spring and follower removed) into a small punch press die that swaged these dimple grooves about 95% flat in relationship to the sides of the box.  Next it is apparent that they filed the inside of the front box sides about 1/2 the thickness of the material to give clearance for the case necks to clear the box's upper inward formed radius.

358 original magazine shown from left side, showing the swaged out should retainer 358 magazine from top, notice how close the necks come to the inside box sides


The removal of these shoulder detents of the box, allows the loaded cartridge to slide forward during firing.  This now positions the cartridge in a possible different location than if the detents were still there.  Therefore it is imperative that in reloading that the overall loaded length of the cartridge be very close to the factory original of 2.750".    It is also suggested that the bullet nose be shaped as close to the factory round as possible for reliable feeding.

RH feed lip has less of an arc and is taller, allowing the cartridge from that side to feed higher.  The distance between front inside of feed lips being .685 to give clearance for the bolt carrier to pass inside the magazine lips.

If you plan on altering a 308 box for 358, you can go internally and grind a small amount (.020) out of the shoulder detents, this will give you clearance while not weakening the box appreciably.  If you try swaging the detent out, you will swell the box to where it may increase in length by about .015.   If this happens, you will need to then file off the front box bottom bump, or forward stop where it hits the magazine latch boss so that the box has enough room to go in at the rear, slide over the rear retainer protrusion, and yet drop down being held by latch on the front.   It also needs to be just short enough to disengage from the rear protrusion. Sometimes just removing the burrs on the back of the box at this rear notch may be enough.  The magazine box's  maximum width (.975), at front of feed lips to ensure feeding.

The original follower was the stainless steel type 2 mentioned above.  If using the newer aluminum follower, it needs to be opened up at an angle on the front RH nest to allow the case to ride up and to the inside as it goes forward and upward into the chamber.  Better yet would be to make another steel follower similar to the original or a Mauser 98.

We can find no apparent changes in the rest of the firearm, 358 caliber s/n 96,4XX when comparing it with a 308 caliber firearm of the same serial number range.  The magazine found on the above 358 has all the indications of being a considerably earlier magazine in comparison to the vintage of the firearm.  It may therefore have been possible that the factory made a considerable number of 358 magazines at the onset, and if indeed sales was slow, maybe the number of magazines in the warehouse exceeded the number of guns assembled.   OR they converted many existing older recalled 308 magazines to the 358 in that they had no caliber designation stamped on them.

We have NOT found any 358 magazines that has that caliber stamped on them.  We suspect there may be, but?   We have heard of one where the original 308 stamping was obliterated however.    Has anyone ever seen a original 358 magazine made on the later type 4 box with the newer extended bottom?   I doubt it, but if you do I would like to have a good close-up photo of this verifying a caliber stamping.


From what information we can find, the model 100 was never produced in 358 caliber from what we can ascertain.  However there may well have been a prototype.


284 Magazines :  The 284 magazine is stamped that caliber and the magazine is slightly different, but only in the length of the feed lips going forward and the shoulder dimple.  In the pictures below the Left Hand picture's LH illustration shows a 284.   Note the shorter magazine lips in comparison to the other 2.  The middle magazine in the LH picture is the later standard 243/308, with the RH illustration one being the early magazine.

In the photo illustrations below, the center picture shows the 3 different bottoms.  The LH illustration is the bottoms that Wisner's Inc uses, in that they did not get any agreement when they bought the tooling from USRA  to use the trademark.   The center illustration is the standard Winchester magazine, with the RH one being the early magazine bottom.

On the right hand side are the rear views of the same magazines showing caliber stampings.  The left one is 284, and the center appears to be a miss-stamped factory 284 magazine with 243/308 designation.   It appears that when they did this they XXXed out the 243/308 caliber, re-stamped the 284 lower front of the box.   The illustration on the right is a standard 243/308 magazine.


The 2 angled relief cuts on the feed lips are there ONLY to allow the deeper bodied follower plus the spring being riveted together to be able to installed into the box with the bottom being installed.

Side views of the 308 magazines on the right, note early one on far right with full length dimple.  A type 3,  284 shown on left Bottoms showing the different stampings with the early flat bottomed one on the right Rear views showing caliber stampings


The followers do not interchange between the 243/308 and the 284, because the 284 followers have to be machined to a larger radius on the shelf to accommodate the larger 284 magnum size case body.


Also in the LH picture below is shown the over-stamped  243/308 caliber of these miss-stamped magazines.  This is not to imply that the 284 uses the same box as the  243/308, but that at the vendors who made the magazines for Winchester, someone forgot to pull the 243/308 stamp out of the master die when they also converted it to the 284 lip/dimple configuration for a run of 284 magazines.   Then these were the result of the salvage operation trying to save a few thousand boxes.

Original miss-stamped factory 284 magazine 284 Magazine spring.  The center point of the "W" always points forward


 
Scope Mount Problems :  Another thing to look for would be if you are using Weaver top mount scope bases and rings.   Originally Weaver stamped the word FRONT on the scope base.  On a subsequent batch the word got erroneously placed on the rear.   So after that they simply left any wording off.  The reason for the word FRONT, was that the cross grooves for the Weaver ring takedown screw are not placed symmetrically, and are designed for placement of the bases to give ejection clearance of the cases at the front.   IF you placed the base backwards AND mount the scope rings like most people do with the take-down knob on the RH side, this knob would interfere with the empty case being ejected.   The case mouth would hit the rear inside of the knob, which many times will cause the case to snap back into the ejection port area, ultimately causing a malfunction.  The other alternative is to place the rings on so the takedown knobs are on the left hand side of the firearm.


Winchester 88 / 100, 284 Win. Feeding Problems :  All model 88284 magazines have shorter feed lips on the front, than the model 100, apparently because of the uncontrolled cycle rate, due to varied operator manipulation.  This allows the cartridges to pop out of the lips earlier than on the model 100's.  Apparently the factory had feeding problems with the model 88 in this caliber and experimented with different feed lip length, as I have seen some almost as long as for the model 100.  These will be the ones that will cause the problems if any.  They finally settled on a much shorter lip length front to rear.   The model 100 lips are about .100 shorter than the 308 caliber.

Many times the problem of the 284 Win not feeding on the model 88 can be traced to the magazine spring.  This magazine needs a stronger spring, especially at the rear.  Since original springs are unavailable, and the one in the magazine usually has weakened over time, the best replacement may be the model 70 magazine spring.   After attaching it to the follower, bend it with pliers to the configuration shown above, which would be about ½ way on the bottom leg, bend the forward section upward at about a 30 degree angle.   Then on the top leg at about 1/3 from the rivet, bend the rear down.  You will now have the follower at a dramatic 85 +- degree angle from the bottom of the first bend, as it will set in the box.   What this will do is to now put more pressure on the rear of the follower, which in turn will push the rim upward with more pressure for the bolt face to push against the case base.  

This spring looks quite unorthodox, but you have to remember that this is a rebated rim case, and the rim has to ride as high AND with as much pressure from the follower to allow the bolt to pick it up on it's forward movement.

Model 100 Disassembly :  The proper disassembly of the model 100 is to first remove the magazine, then remove the forearm screw AND the trigger guard screw behind the trigger guard.  Now pull the operating handle all the way to the rear.  While holding it to the rear, pivot the barrel unit up out of the stock.  The rear of the receiver is held in place by it fitting in a notch in the recoil block in the stock.  The reason that the operating handle has to be rearward is to allow enough clearance for the side rods from the handle to the gas cylinder unit to clear the slot in the forearm section.  Since these rods are hidden in the forearm with wood covering them except when the handle is pulled all the way back many gun enthusiasts do not realize they are there. 

Model 100 Gas System Problems :  Failure to close the bolt and therefore not fire can very often be traced to a rusted gas piston.   More often however, you have problems or can not open the bolt.  The gas piston will rust inside the gas cylinder, seizing the two together.  This piston is pinned into the operating slide assembly.  The cylinder is held into the barrel lug by a nut on the forward end.  If the operating handle is hard to move or will not move rearward, you very well could have a rusted situation.  This can be from slightly resistant to pull rearward to impossible to move.   You can tap the operating handle to try to move it.  However this slide assembly that the operating handle is part of is a stamped out sheet metal that the bottom portion of the handle is silver soldered onto.  If it is stuck to where you beat on the handle enough, you may break the silver solder bond loose.  If so save the broken off handle section so it can be replaced.

If you can move the handle slightly, try to spray some penetrating oil in around the front of the barrel channel of the forearm.  Hopefully some may get inside the cylinder to help in your endeavors.

I know one gunsmith who in his early years of the trade could not get a customers gun apart because of a rusted situation, his method of removal was to break the stock to get the gun apart.  Replacement stocks were available in those days, now the stocks are worth more than the gun to someone in need.

Replacement stainless steel pistons are available from Brownells.

If the gas cylinder is rusted so tightly into the operating slide assembly that it can not be pulled rearward, there is one solution.  You will by now have some movement of the barrel away from the forearm.  Select a long punch  that will go in between the barrel  and the forearm.  Locate the small retainer ring that locks the gas cylinder sleeve/plug in place, hit it hard enough with the punch to break it.  Now you can use a large long screwdriver to engage the slot on the end of this plug/cap, unscrewing the plug from the cylinder which is mounted in the barrel lug.  The cylinder should not rotate as it is rusted onto the gas piston.  This may take a bit of effort if the plug is also rusted in place, but with some persistence and penetrating oil, you should now be able to unscrew the plug.   What you have done is to remove the “cap nut” that holds the gas cylinder into the barrel's gas lug, the cylinder being rusted in the operating handle, it can now be retracted out of the lug, allowing the handle to be retracted.  This information was supplied by a long-time Winchester warranty gunsmith Walter Lodewick, who worked on them at that time.

Model 100 Broken Operating Slide Bars :  Another thing that is common is that the attachment pin area of the operating slide where it attaches to the breech bolt sleeve can become broken.  This is usually on one side.  The gun will usually continue to function, but with slight binding when trying to open it by hand.  If allowed to continue, it may even break off the other side of the operating slide at the bend where the unit is pinned together.

If this is broken, you will not be able to find any replacement ones.   You will need to recruit the services of a GOOD GUNSMITH welder.  This is not just anyone who can purchase a Oxygen/Acetylene welder set, but someone who has experience welding heat-treated formed sheet metal.  This repair needs to be stronger than the original part by willing a filler bead in the "Vee" of the sheet metal behind the handle.  It needs to be annealed before the repair, welded, cooled, and some form of heat-treating then performed before put back into service.  There is one gunsmithing business that I have heard of that charges $125 exchange for a repaired unit

Model 100 Operating Handle Free, But Not Retracting all the Way :   This usually can be attributed to the owner  trying to disassemble the gun using the thought that the trigger housing will come out first from the bottom.  They can not get it to come out (usually bending the side rails in the process) so they reassemble it, only to now find that the handle will not operate.  What they have done is that the safety somehow got pushed off, in the process, they accidentally pulled the trigger, not knowing what has just happened, when they retightened this unit the hammer’s top rear corner is now bound up between the bolt sleeve and the head on the rear of the firing pin.  The trick is now to remove the rear guard screw, pry the trigger guard assembly down far enough to reach inside, then recock the hammer with a long hooked rod.
 

Model 100 Bent Trigger Guard Housing Rails :  Sometimes the model 100 will not feed properly, when this is encountered, it is usually the result of someone who thinks the trigger guard assembly can be removed from the gun first out the bottom.  When these are encountered they will have to be straightened.  What the bent rails do is that since the rails hold the bottom unit in the gun, and they hold the rear magazine latch, the magazine now is not in the proper position to feed ammo.  Usually the rear will be bent down way more than the front, this then allows the magazine rear to be positioned too low so the bolt unit will override the rim section of the cartridge, causing miss-feeding.   The rails will usually be bent at the location of the front retainer pin in the trigger housing itself.  They could also be bent right at the rear of the front bracket unit.

To correct this, I usually lay the housing upside down on a 6" vise and tighten the vise just enough so the rails lay snuggly on the top of each side of the vise jaws.
  You can then by using a flat bar on top of the rail, hammer the bar down so it is straight with the rear of the bar that is riveted into the aluminum trigger housing.  Try to get both bars
straight but the important part is that the front be in line with the rear.  A little bends in between is not critical.  However you need to be careful and not pop the rail's front silver solder to the front bracket unit loose.  If this happens, that will have to be re-silversoldered back.


 Reloading :   If the ammo is reloaded for this firearm, it has to be loaded the same overall length and nose shape as factory ammo in order to give reliable feeding.   Just because it fits the reloader's book specs. does not mean it will reliably feed and function.  It also has to be loaded to the factory velocity levels for any semiautomatic to function reliably.


Model 100 Trigger Lock   The model 100 originally had a trigger lock system to eliminate doubling, but after two years of production in 1963, the factory decided that it caused more problems than good.  Because of these problems, they discontinued its use and recommended that these parts be removed from all existing rifles when they later came into a gunshop for repairs.


Replacement magazine Assemblies for Model 88 & :    These factory magazines have been factory discontinued  for some years.  The only source as of 1996 is Wisner’s Inc 360-748-4590.  This firm purchased the original tooling from USRA.  They left the tooling with the original vendor in Connecticut,  who stamped the parts out on the original dies for us until 2003, then when this company wa sso tied up with military M16 contracts, this tooling was sent to a tool and die firm in Portland OR, who stamps out, bends and spot welds the bodies.    Wisner’s does all the remaining machining and assembly.  The only difference in these magazines is that there is no “Winchester” name stamped on the bottom plate as they did not negotiate with Olin (the original Winchester owner) for the rights to use the Winchester name at that time.  Wisner’s is also having these magazine boxes made out of a stronger material to help eliminate any possible chance of distortion and to maintain the feeding qualities. 

When Wisners reorder from the current tool and die shop, the quantities for boxes usually run between 4000 and 5000 at a time.

Wisner's does have a few magazines assembled with original "Winchester" bottoms and so stamped.

The original magazine follower moulds were also purchase from USRA at the same time.  Different versions of magazine springs were used over the time span by the manufacturer.   Wisner’s developed a universal magazine spring that can be used in the model 88 & 100 magazines as well as most bolt action rifles.


Stocks : The stocks are somewhat prone to breakage since the large open hole for the magazine weakens the stock.   Excellent original replacement ones usually sell for almost as much as the gun itself because there are not many left.  Replacement stocks are available from the different sources.


------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

WINCHESTER MODEL 100 FIRING PIN RECALL -   A notice dated 7-1990 relates the following

 “PRODUCT SAFETY WARNING AND REPLACEMENT NOTICE.   Attention owners of Winchester model 100 rifles and carbines please read this notice.  In July of 1990 the following product safety warning was issued by Winchester.  It has come to our attention that the firing pin in the Winchester Model 100 Rifle or Carbine may break due to use and metal fatigue and become lodged in the breech bolt face.  If this occurs, the firearm may fire before the action is locked causing severe damage to the firearm and possibly injury or death to the shooter and bystander.

WARNING DO NOT SHOOT YOUR WINCHESTER MODEL 100 RIFLE OR CARBINE.  Repair and replacement.  A new firing pin has been designed to replace the firing pin originally made for the Winchester Model 100 Rifle and Carbine.  The new firing pins will be available in April 1991.  If you own a Winchester Model 100 Rifle or Carbine, please send your firearm to one of the authorized Winchester Model 100 Firing Pin Replacement Centers indicated below.  Your Winchester Model 100 firearm will be inspected, the firing pin replaced and tested and the firearm returned to you.  The inspection, replacement/testing and return postage will be accomplished at no cost to you.  If other repair or maintenance work is authorized by you to be performed on the firearm when the firing pin is replaced, such work shall be at your cost.”

W. R. Long Gunsmiths 
2007 Brook Road North 
Cobourg, Ontario K9A4W4
Canada 
Frank LeFever & Sons 
RD 2 Box 31
Lee Center, NY 13363
USA
Bolsa Gunsmithing
7404 Bolsa Avenue
Westminister, CA 92683
USA 
Nu Line Guns
1053 Caulks Hill Road
Harvester, MO 63303
USA

                                                                        
If you have any questions concerning this notice, call Winchester Product Service 1-800-852-5734 or write to Winchester Firing Pin replacement Notice, PO Box 10 Cottage Hills Illinois 62018  Attention Product Service Dept.

 ----------------------------------------------------------------------------------

The following is Wisner's rendition & info on the subject.

The difference in the old firing pin and the new one is as follows.  The old replaced style, was totally lathe tuned (round).  While the new recall style is similar in lathe turning on the front and back, but in the front midsection it has two flats milled, one on each side.  This makes the center section stronger.  Also replaced is the bolt sleeve lock pin  (firing pin guide) which was made to accommodate this different shaped firing pin

 Part number  for the new parts are, firing pin =1391ND, bolt sleeve locking pin =1491ND

The word was at the time this recall was in process was that if the firing pin would break at the mid section and still remain in the gun as two pieces, the possibility of a premature discharge before the bolt was locked was possible.  This apparently was caused by the firing pin tip (now not having a retracting spring) to be stuck forward, and thereby slam-firing the cartridge upon chambering.

The responsibility for the recall apparently was on Olin, as they were the parent company at time of manufacture.  Olin set up regional recall centers at three established US gunshops. There was a manufacturing delay in the replacement firing pins, and a backlog occurred, also some collectors did not like the idea of shipping their guns long distances.  Olin then also authorized other gunshops to make the required alterations.  Upon completion of the recall, the shops were to test fire the firearm and to stamp an assigned letter on the inside top of the receiver as seen thru the magazine well with the bolt retracted. The letter “B” represented Bolsa Gunsmithing, “L” was Lefever, and “N” was for Nu-line Guns.  The letter “X” apparently was for all the other independent shops.  However this identification  information did not get communicated to some of the smaller shops at the start of the project.  The only way to tell if the gun as been modified, if the ”letter” is not present, is to take the barrel & action out of the stock, remove the trigger guard assembly and the try to rotate the firing pin by twisting it.  If it does rotate, then the firing pin recall HAS NOT been performed. 

 

Copyright © 2004 - 2014 LeeRoy Wisner  All Rights Reserved

Back to Ramblings

Originated 05-17-04  Last updated 11-23-2014   ***
to contact the author click here