7.62 M1 Garand sticky chamber

[browningautorifle]

Then go ahead and do the washer. Let us know.

[Chuckindenver]

remember...)( is a country mile when it comes to headspace..when adding even a paper then washer, your pushing that barrel out, pushing the chamber out,,extending the headpace out to dangerous lengths.
only fix on the barrel is to change it, if it were a bolt action or single shot, turning the shoulder, and the breach face would work.
on a semi auto with gas system, it doesnt work, shortening up the barrel, will break parts down the road..
a new commecial barrel costs less then 200.00

[boatbod]

Difference between go and field is 0.008" if I recall. Definitely do-able, but requires care.
What I'm going to do before exploring that avenue is go shoot what I've done so far and see if further tinkering is necessary. Looks like I'll have more time on my hands after Christmas, but sadly less spare $$ for a month or two. Experimentation not spending will be the name of the game.

[Chuckindenver]

its been my experiance, every time iv tried a washer, even a thing brass or copper one thats thinner then paper, it was unsafe, on square threaded shouldered barrels.
the only square threaded barrel its worked on, is a Krag, as it crush is at the breach face, and a rimmed case.
i can relate to the less money, more time thing...

[browningautorifle]

If you re-created the crush factor with your pien of the shoulder, your barrel will be sufficiently tight to hold solid. You can't unscrew it with your hands anyway. I've had some very light torque barrels do just fine. Have faith. It'll be fine.

[boatbod]

Oh I wouldn't try to add a washer or shim without removing some material from the barrel shoulder first.

What I'd do is face off the shoulder to clean it up, screw the barrel into the receiver at say 10 o'clock and then measure with feeler gauges to determine how much gap I had. (e.g. 0.006") Next step would be to make a washer at some arbitrary but manageable thickness (e.g. 0.090") then do the math to figure out how much extra material had to be removed from the barrel shoulder. In this theoretical example, that would be 0.084".

The barrel should come up hand tight at 10 o'clock and would then need to be torqued until it reached index at 12 o'clock. Theoretically headspace shouldn't have changed by more than a thou or two if at all, since the threads would be engaging at the same place.

[JBS]

A recommended minimum thickness for your breaching washer is .050 plus what is needed to index at torque. Most smiths’ experience failure doing this because they attempt to use a shim washer instead of cutting the shoulder forward and making or using a true breaching washer. Good luck to you.

[boatbod]

If you re-created the crush factor with your pien of the shoulder, your barrel will be sufficiently tight to hold solid. You can't unscrew it with your hands anyway. I've had some very light torque barrels do just fine. Have faith. It'll be fine.

It's definitely light torque, but a fair bit more than hand tight. I definitely want to shoot it before doing anything further, but those darned family obligations are getting in the way!!

[boatbod]

Finally got to spend some time at the range.

The good news is that rims are no longer being destroyed. The empty cases looked pretty good, with the occasional ding at the mouth, but otherwise undamaged. Accuracy was pretty good considering my general lack of time on iron sights. Most shots were going into a 4" group at 100yds when fired from a bench. At 200yds I was reasonably reliably hitting a torso sized metal plate.

The bad news is that I'm still experiencing failure to feed once or twice per clip. Mostly when that happened the chamber is completely empty, however sometimes a partially fed round had hung up at an odd angle just off the mouth of the chamber.

On the surface this seems like a short stroking problem since I can't imagine how else you'd end up with an empty chamber, however, I do not recall a single incidence of the bolt failing to lock back after the 8th round was fired. Maybe friction from the bolt rubbing on the next round is enough to slow it down if it's already moving more slowly than in should?

Back to the workbench... I'm going to polish up a few cases to look for rings, and then I suppose I better mic the piston and find a way to gauge the gas cylinder.

[browningautorifle]

That's probably right. I wish I was a bit closer and it would be easier to help. If you can get another shooter(experienced) to watch, you may get some insight. What ammo are you using again? Maybe it doesn't have the poop? I don't think it's friction. There's sticky here somewhere in the M1/M14 forum to help with the malfunctions.