Home Forums Hunting & Shooting Gunsmithing M100 Winchester Firing Pin

I got mine in about a week. They wanted the old pin and the serial number. I was impressed with their speed.

11 days for mine. I used priority shipping too. PM'd fatjack earlier.

I am excited! Any of you cats have a link to an actual rifle schematic? Not just a list of parts, but the pictures too? I learn that way much faster...BELIEVE ME!

Disregard...ain't Google grand???!!!

http://www.wisnersinc.com/exploded_views/Winc-100.htm

Back to the drawing board. I tried her today and had several failures to extract with reloads and some military rounds. I will try it with some commercial factory loads after my next round of tinkering. I suppose I will do some more chamber work and replace the extractor and plunger with another one of the new ones I got from Numrich. I don't know of anything else I can do.

I do have a question about what stops the forward motion of the operating rod.

The end of the operating rod has the cylinder into which the gas bleeds in from the barrel to work the action. The forward end of the rod extends a small amount out the front end of the threaded gas tube onto which the gas cap with the little retainer screws. Screwing the gas cap all the way until it stops pushes the cylinder back a little. With the cap screwed in, the operating rod's forward motion is stopped by the cylinder hitting the gas cap. Is that the way it should be?

If I unscrew the cap a little, the retaining does not fit and the operating rod's forward motion is halted by the pin connecting the rod to the bolt. That seems like a very fragile way to stop the forward motion.


I polished the chamber and neck again and put in a different extractor. I tried to put in a new plunger that holds in the extractor, but the new one was a little too long. I will try some factory loads next time out to see if I can not get her running right. Any suggestions are always welcome.

Ok so it fires with the new firng pin. No problems there?

1. Make sure the extractor slides back and forth easilly. Sometimes you need to file or hone just a little off the sides so it slides freely.

2. Make sure your gas piston is NOT pitted.

3. From what I could tell in your pic, your chamber didn't look like it was too bad judging by the condition of the fired case. Therefore, I don't think it is your chamber you should be concerned with.

4. Make sure the gas cylinder cap is TIGHT, then put the retainer in place.

5. This may sound real dumb, but make damn sure the port in the barrel is not plugged. Use a torch tip cleaner or similar tool to clean the gunk out of it.

6. Polish the outside of the gas piston and then clean the heck out of the inside of the gas cylinder. Make sure the piston slides in and out of the cylinder smoothly. You don't want any slop in the fit of these two parts, if there is one of them or both may be worn too much. Lightly oil these parts with something like rem oil. When I say light I mean a little spray and then whipe most of it off. Don't need a lot of lube there, but just enough.

7. Usually if it is jamming or failing to feed you have a problem with the magazine but from your description it sounds like it just isn't extracting.

8. After you do all this, try some cheap factories like the rem corelockts (150 gr.). It should function with these without a hiccup. By the way, Redneck is the professional here so you may want to pm him and he will probably further assist you. Good luck with it.

Thanks, BSA. I do have a problem with #4. The gas cylinder cap is not tight at all when the retainer notches are lined up with the notches in the stud on the barrel. It can be tightened about another 1/16 of a turn before it becomes tight. I have to back it off to get the retainer to fit into place. The cap is quite loose.

The problem does not seem to be getting the bolt to the rear but rather pulling the case out of the chamber. The rifle jams when the next live round tries to feed into a chamber occupied by a partially extracted empty case. The last round I fired today stayed in the chamber while the bolt locked to the rear.

Numrich has Winchester extractors and replacement extractors. The one I put in for today's shooting was a replacement extractor. I put in a Winchester one today when I got back from the range and will try that next trip.

The loads I have used were some of my reloads in LC cases and a Greek military surplus round a fellow shooter gave me. I have a bunch of Win/Rem/Fed factory rounds I will try next time. She may not like military cases.

Thanks to you folks for talking me through my attempts to get the old girl running right. I appreciate the help and may need some more in the future.

No problem, there are some very knowledgeable people here on the subject. Redneck was probably busy today or something, but I'm sure he will chime in when he runs across this thread again. He'll point out where I may be wrong too . Let us know how the winchester extractor works out for you. It's strange the retainer isn't fitting correct. That is with the little ears facing to the rear of the action isn't it??? Make sure you check the actuall gas port in the barrel too as they will not function properly if it is plugged. Let us know. The winchester model 100 is a sweetheart to shoot when everything is working as it should. Good luck to you with it.

This is the way the cap looks with the retainer in place.


This is how far the cap can be screwed in with the retainer removed. Notice that the shoulder on the gas cylinder to the right of the barrel lug is tight against the barrel lug in this picture.


This picture shows how much play there is between the gas cylinder and the barrel lug when the gas cap is screwed in all the way. Notice the gap between the barrel lug and the shoulder on the gas cylinder.


This picture shows how far the gas piston extends beyond the front end of the gas cylinder with the gas cap removed.


The gas cap with the gas plug staked in place. I assume the position of gas plug was adjusted at the factory and then staked in place.

I want to get her shooting right by October so I can run into this fellow with a rifle that works.

Your're on to something here. That doesn't even appear to be the correct cap for the pre 64 type or maybe mine is incorrect, but either way it is different than mine and mine is definately pre 64 (made in 1961). The gas cylinder is susposed to slide into the gas cylinder housing which is an integral part on the underside of the barrel. When the gas cylinder stops securely against the shoulder there should be proper alignment of the gas port in the barrel and the hole in the gas cylinder that makes the gun function the way it is susposed to. If there is slop there or the gas ports don't line up you will have problems. My cap has many slots cut in it so I can rotate it until it is tight and then put the retainer in the one it lines up with best. If it were mine the first thing I'd do is check to make sure the gas port's line up, from there I'd check out all parts to see if parts are worn past their usable limits. I'm thinking something is really worn out or someone stuck the wrong cap on that rifle that's why I'd start precisely measuring things. Now I feel like tearing mine apart just to check some things out, I've seen caps like yours and like mine. Also they make different plugs for the 243, 308, and the 284. That may be where you problem lies (somone may have put the wrong plug/cap on your rifle if it's ever been replaced). My best educated guess.

The cap on mine is made of two parts, a sleeve and a plug. The plug is screwed into the sleeve and is held in place by staking them together once the proper adjustment has been made. The single set of slots should be all that is necessary if the adjustment is proper. My serial number is around 25,000. That puts it in about the same time as yours.

How is the forward motion of your slide stopped? Mine is stopped by the gas piston hitting the inside of the gas cap. I don't want to change things around so that I put that stress somewhere it is not supposed to be.

The gas ports seem to line up fine. The gas port in the barrel seems fine.

This gas cap could very easily not be original. The old gentleman who had it was known for messing with guns. He was the one who had a beautiful 1911 made in 1918 chromed.

I have been able to get another .308 gas plug but have not found any new gas caps. A new slot would be easy to cut in the one I have if that is necessary. I certainly do not like to start cutting on things unless I know for sure that nothing will be damaged.

I understand that. What I'm saying is the plug may not be correct for that caliber (308), as they had different plugs for each rifle cartridge made for the 100's (243,308,and 284). The whole assembly is different than mine, but I think mine was original. They had problems with some of the originals and made the change to the newer style like the one you picture. I have no problems with mine so I'm keeping it the way it is. I'd examine the new plug you have for the 308 and see if there are any differences. May just be like I said and the wrong cap/plug installed on your rifle. One thing I do know is it isn't going to work for chit being loose like you pictured. The shoulder has to be snug up against the integral gas cylinder housing. It can't be sloppy loose there or your gas system will fail to work properly.

I tried her out today with some Winchester factory rounds and had no problems. I also tried several of my reloads that did fine also. All dozen rounds I fired fed and ejected as they should with no strange marks on the rims.

I had replaced the extractor with a factory one and had also replaced the gas tube even though the old one looked exactly like the new one. Looks, however, can be deceiving.

I will do some more shooting soon and hope I run into no more problems.

I am still curious about what stared the problem in the first place.