Possible correlation between feeding and how worn an M1 Carbine is?

I was wondering if there is a possible correlation between how well a carbine feeds (functions) and how new of a condition, or old and worn it is.

My original Inland is 95% to 98% finish and an ME of less than 1 (probably about "0").

My Standard Products mix-master's barreled receiver (and most other parts, too) is about 90%+ original finish, and an ME of between 1 and 2.

Both appear to have been shot very little, compared to many of the carbines I have had. Both function flawlessly with GI 30 rounders, no matter what ammo I use.

Granted, I replaced recoil springs in both prior to shooting, as a matter of course, and ejector and extractor springs in the mix-master. I still wonder, however, if old, much more used carbines are more prone to malfunction than lesser used ones.

While this is no way scientific, I wonder what experiences others have had

I firmly agree that a low mile weapon will always work better than a beater. The Garand gets away with this to a certain extent because of the full power cartridge. The carbine is working with less gas and less moving parts, but it isn't as tolerant of wear. If the trigger housing is sloppy and has significant movement that just exacerbates the problem. I've always felt that the weak link is the magazine. It isn't robust at all and the two tiny nibs that engage it are kind of a joke when compared with other military weapons. Certain steps can be taken, like polishing the feed ramp, careful cleaning and lubrication, and ammunition quality can make most of this a moot point. Keeping a good recoil spring in there solves many problems.

Ever look at a firing pin with a glass? The tip can look like a rough pitted road. Looks great to the naked eye, but in reality it is a piece of scrap. I hate to bring this up, but how many useless worn out parts are called back to duty by part swappers? People might be selectively assembling a problem carbine. If a part is purchased a a part, there is usually a reason why it isn't inside some carbine.

I think that the weak spot of the carbine is the slide, particularly the tabs. I like to lightly grease the receiver slot, as well as the bolt lug recess.

The two biggest problems that surface with older carbines are the extractor group and the recoil spring. The extractor group quite often is forgotten when cleaning a carbine. Old grease and dirt get into the plunger and spring causing it to bind and not allow the extractor to close on a cartridge rim. The extractor can chip or break and will also creat functoning problems. These need to be checked, cleaned and replaced if need be. Get a bolt tool if you intend to take the bolt apart as you will need it.

The recoil spring should be 10 1/4 inches long. If it's less then a new spring should be installed. Use a USGI spring and not one of the after market high speed springs as they can creat more problems then they are worth.

It is not very often a trigger housing will be too loose to work properly but if it does then do not try to tighten the lugs on the receiver. They are hardened and can snap off. Work on the trigger housing lugs that can be spreaded apart a little bit to help tighten up the action. A loose housing will not hurt accuracy as it has nothing to do with it.

A worn tab on a slide again does not happen too often. If the tab is a bit worn then the slide arm can be slightly and I mean slighty bent inward to take up some of the play. If the tab is very worn then the slide needs to be replaced.

The gas system on a carbine does not need to be taken apart for cleaning so leave the castle nut and piston alone. A little bit of hoppies on the piston will work. If for some reason the piston has to be removed then get a new castle nut as most often the old one will strip coming off. Do not over tighten the nut when replacing it as the gas cylinder can crack and that means a barrel replacement.

Didn't mean to get long winded here.

The FIRST thing I do when I get a new carbine is the take my bolt tool, completely strip the bolt, and check all of the above. A bolt tool is a must, if you are serious about thoroughly cleaning the carbine. Pipe cleaners in Hoppe's are great for cleaning firing pin hole and ejector hole.

On the un-messed with Inland, I am running original extractor, plunger, and spring, as well as original ejector and spring to keep it "original." I did replace the recoil spring with a new 10 5/16" USGI one, though, as its was at 10 1/8." The Standard Products mix-master, since it is my duty weapon, I replaced not just recoil spring, but ejector and extractor springs, and put a new USGI Inland extractor. I do not use grease on mine, but do use Breakfree as it is seems to be more viscous.

I really do believe that trigger housing/receiver fit is crucial to reliability. The Inland is excellent fit, as is, with nil as far as wiggle. The Standard Products is snug, also, but that was accomplished by someone slightly peening the rear lug of the trigger housing to make it snug in the rear lug of the receiver.

Quote:

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Originally Posted by Bruce McAskill

The two biggest problems that surface with older carbines are the extractor group and the recoil spring. The extractor group quite often is forgotten when cleaning a carbine. Old grease and dirt get into the plunger and spring causing it to bind and not allow the extractor to close on a cartridge rim. The extractor can chip or break and will also creat functoning problems. These need to be checked, cleaned and replaced if need be. Get a bolt tool if you intend to take the bolt apart as you will need it.

The recoil spring should be 10 1/4 inches long. If it's less then a new spring should be installed. Use a USGI spring and not one of the after market high speed springs as they can creat more problems then they are worth.

It is not very often a trigger housing will be too loose to work properly but if it does then do not try to tighten the lugs on the receiver. They are hardened and can snap off. Work on the trigger housing lugs that can be spreaded apart a little bit to help tighten up the action. A loose housing will not hurt accuracy as it has nothing to do with it.

A worn tab on a slide again does not happen too often. If the tab is a bit worn then the slide arm can be slightly and I mean slighty bent inward to take up some of the play. If the tab is very worn then the slide needs to be replaced.

The gas system on a carbine does not need to be taken apart for cleaning so leave the castle nut and piston alone. A little bit of hoppies on the piston will work. If for some reason the piston has to be removed then get a new castle nut as most often the old one will strip coming off. Do not over tighten the nut when replacing it as the gas cylinder can crack and that means a barrel replacement.

Didn't mean to get long winded here.

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I agree with this but will add another third biggest problem in an M1 carbine. A dirty chamber. Most clean the bore with a 30 cal bore bush but it is to small to clean the chamber. I use 9mm brushes to clean the chamber.

I look at the slide and think that a single recoil spring has to induce some side loading, so grease the slots along the side of the barrel and receiver notch on the right side. In addition, I use the white GI oil which stays where it is put and works great. A lot of those worn out slides are caused by WD40 or 3-1 oil use. Amen to what Bruce says. How can an assembled bolt be considered clean by soaking in some solvent or boiling it? The holes for the plunger are full of carbon, dirt and unburned powder. The fact that the parts are much smaller than the big rifle makes cleaning them and looking at them that much more important.

While most people want to look at the carbine as a collector item, to me it is an operational weapon. If it is going to be a shooter for me, it is going to be up to standards. I want EVERY piece to be up to standard. I use the specs in the Depot level rebuild chart to check everything. I learned (the hard way) to only buy parts from reputable people to make sure what I got was in spec. I have 4 slides in a drawer right now that have tabs out of spec. I won't use them and i won't sell them - they are permanently ot of circulation. I treat it like I did my M-16 and my service pistol. Up to standard or its repaired. I also use the later parts in the shooters - slides, prefer round bolts, up to date springs, M-2 stocks, mag relases, etc.

If you are going to shoot it, make it the best shooter you can. take care of it and it will take care of you.

Just my two cents worth.

Speaking of feeding, something to look for is gross wear on the feed ramp on carbines that were used as M2's and then converted back to M1. Not that it really affects anything, just an indicator of very heavy use. It is manifested by very clear grooves worn in the ramp, one from each side of the magazine.