M1A Issues

[Shoots 700's]

I have a M1A that I have had for a couple of years. I hand load for it and recently I will have a round go off and nothing will happen once the gun goes off, no bolt movement or ejection. It basically goes single shot. It hen need to rack the bolt to clear the fired case and feed a fresh round.

The gun it clean and I checked everything, any suggestions


Jeff

 

[insight3b]

Is the spindle valve turned on?

 

[Shoots 700's]

Yes it's on, the gun doesn't do it every time I shoot. Yesterday I shot 8-10 rounds just fine, then it would act up.

 

[That Guy]

By everything, does that include the piston? (AKA the gas cylinder if you'r looking at a detailed manual)

 

[Shoots 700's]

I have checked everything, I guess I cannot explain why it is doing this intermittently

 

[BCP]

Does it pass the tilt test and is the gas plug screwed on tight?

 

[That Guy]

how about your hand loads... have you been going light on the powder or recently switched something?

 

[Shoots 700's]

Plug is tight, what is the tilt test?

 

[Shoots 700's]

Hand loads are 41.5 of h4895 and 168g Nosler CC. It's what I have always run

 

[bluto51]

You should be able to hear the gas piston slide back and forth when you tilt the rifle. How many rounds have you shot through the rifle since you reamed the carbon deposits out of the gas plug and cylinder? Check out this:
Fires, ejects but is not reloading - M14 Forum

 

[Shoots 700's]

The rifle only has about 250 rounds through it. I did a good cleaning, but will clean again and double check.

 

[Shoots 700's]

System is clean as it can be, spindle is open. I guess I will take it out again next weekend and shoot steel to see if it continues.

The gun is fun to shoot and I have no trouble hitting hanging steel at 300 yards. I sure hope I can track this down.

 

[BCP]

System is clean as it can be, spindle is open. I guess I will take it out again next weekend and shoot steel to see if it continues.

The gun is fun to shoot and I have no trouble hitting hanging steel at 300 yards. I sure hope I can track this down.

If it's clean, passes the tilt test, the only thing I can think of is that your handloads aren't sized properly so every now and then when fired one sticks in the chamber so that you have to manually extract it. Might want to try posting on a dedicated M1A forum.

 

[Unknown]

Case length was always a bugger in my M1A. If the cases were even a teensy bit too long, the rifle would not function right. Once I started making sure that all cases were no longer than 2.000, the rifle ran like a Swiss watch.

 

[Shoots 700's]

I will look into the length, I have had no issues running them at 2.005 with this load.

 

[r2048cab]

Tilt test you mean ? Go to M14 Forum & check Ted Brown forum " tilt Test " & you will get a lot of info about your M1A

 

[kraigWY]

It isn't the rifle, its the ammo. 41.5 grns of 4895 w/168s is about as perfect load as you can get and will work the action:

The problem is, re-sizing the brass. Bet you lunch if you run your resized brass in a Wilson (or similar) case gage you'll find out its too long, not the neck but from the base to the shoulder.

For gas guns its critical to properly set up your sizing die to size the case to specs. You can get by with bolt guns using the brass that has fired in the same rifles, not true with gas guns. The shoulder has to be set back to specs.

Load some new brass, or shoot some factory rounds, bet you wont have any problems cycling the action. If it does, then use a case gage to set up your sizing die and you've fixed the problem.

 

[Shoots 700's]

Thanks Kraig, I will case gauge them and see if that helps. I have never had any issues with any AR-15 or AR10 doing this, insure hope you're right!

 

[Name Enough]

I am on my 4th M1a and have experienced the same. Ist issue was gas port not alligned correctly. Second was light hand loads. I have installed a Schuster adjustable gas plug which will allow you to adjust your gas to your load. Well worth the $50 it costs.

 

[NoExpert]

Zero movement? Hmmmm. I've seen an SAI rifle with an out of spec firing pin safety bridge that locked up the action and wouldn't cycle at all. Check your brass for sure. Also dry fire the rifle and try to cycle the action a few times with the muzzle down and then up.

 

[Crus75]

It isn't the rifle, its the ammo. 41.5 grns of 4895 w/168s is about as perfect load as you can get and will work the action:

The problem is, re-sizing the brass. Bet you lunch if you run your resized brass in a Wilson (or similar) case gage you'll find out its too long, not the neck but from the base to the shoulder.

For gas guns its critical to properly set up your sizing die to size the case to specs. You can get by with bolt guns using the brass that has fired in the same rifles, not true with gas guns. The shoulder has to be set back to specs.

Load some new brass, or shoot some factory rounds, bet you wont have any problems cycling the action. If it does, then use a case gage to set up your sizing die and you've fixed the problem.

+1
Also, case head may be 'sticking' as well. What kind of brass do you use? Try a small base die as well, you may not be getting enough sizing at the case head area, just above the web. Check head space as well. Do you clean the chamber? if not, this could lead to sticking cases. Try using a .38 or .40 cal bore brush attached to a wooden dowel rod, taped together with duct tape, you'd be amazed how well it holds,..throw on a patch with Butch's then swab out the chamber good, try getting up into the neck area best you can then dry patch it out.. The .38 will be loose fit, the .40 will be tight fit, but both will work, you don't want to use a brush with stiff bristles, get one that has a little more 'flexible' bristles..
Once you 've done this and if no luck, try breaking the gun down and inspect each piece visually and verify there is no metal to metal contact areas that are oddly worn or deformed. Be sure you have proper lubrication at all contact areas. Check firing pin areas also.

 

[insight3b]

Are you running the piston wet or dry?

 

[Valken]

If it's clean, passes the tilt test, the only thing I can think of is that your handloads aren't sized properly so every now and then when fired one sticks in the chamber so that you have to manually extract it. Might want to try posting on a dedicated M1A forum.

Bingo. If I had to guess that would be it. I had a problem many years ago with to long a head space. The bolt would slam home but it would push the brass against the chambers wall. then i pull the trigger and the case would either still be chambered or short cycle and I would have an empty chamber. You can not bump the shoulders back for an M1A/M14. you must full length resize