SA M1A Loaded Problems

[Vt.birdhunter]

Having large numbers of FTFs.

When I attempt (after waiting) to remove the round the bolt cannot be moved by hand. A few taps with a wood block on the bolt handle, and the round pops out. Slight dent on primer, round unfired. Black residue around the widest portion of the case closest to the bullet.
Rifle is clean.

Happens 3 out of ten rounds with some ammo. Most recently with BVAC 150 gr FMJ bimetal, once fired brass reloads from CTD. Shot great when it worked. 10 shot groups at 200 yards were under 2".

Tends to happen with a friends reloads as well (150 and 168gr match...different crimps tried, all have had the same results.)

Silver Bear, Federal fusion and a few other factory ammo brands seem to feed fine. Been happening since I bought the rifle new about 500 rounds ago.

Whats the problem?

Separate issue: My Sadlak Mount has the tendency to catch ejected brass, towards the front of the mount over the chamber entrance. Creating a tiny bit more clearance in the mount with a dremel would seem to fix it, what else should I try first?

TYVM for the advice.

 

[warbirdlover]

I'm sorry but I don't understand most of these abbreviations (FTF's etc).

 

[Slamfire]

When I attempt (after waiting) to remove the round the bolt cannot be moved by hand. A few taps with a wood block on the bolt handle, and the round pops out. Slight dent on primer, round unfired. Black residue around the widest portion of the case closest to the bullet.
Rifle is clean.

You may be playing an elaborate game of Russian Roulette.

Sure sounds to me that your rounds are so oversized that the lugs are not fully in engagement till the hammer nose cams them into alignment EEK!

If that is what is happening then the lugs are not fully engaged, the firing pin tang is still out of alignment with the bridge slot, and you are a candidate for an out of battery slamfire.

You have to take a wooden block to open the bolt!!!. That ought to tell you that you have an interference fit going on.

You must always full length resize your cases, you should be using a small base die, you should set your shoulders back about .003” or just size to gage minimum.

Always use a case gage in setting up your dies, if you are having these sort of problems in your rifle, I am confident that you are not.

 

[GONIF]

FULL LENTH RESIZE . Shoot only you own reloads .give the chamber a good cleaning and a polish .

 

[Tim R]

What Slam Fire said or it could also be an extremly dirty chamber.

Black residue around the widest portion of the case closest to the bullet.
Rifle is clean.

;

 

[kraigwy]

Slamfire got it.

You need to resize your brass to specs. Don't matter if it came out of your gun or not. Gas guns stretch brass from the shoulder to base.

As pictured by Slamfire, never reload for any gas guns without useing a case gage.

Lots of things can happen from difficulty to extract live round, failure to fire, failure to cycle. on in worse cases slam fires. (slam fires are not so common on ARs but are one M14/M1A, M1, etc)

Many people, my self included, when running the line on a high power match carry case gages, we check suspected ammo and if it doesn't fit the gage, you are not allowed to fire it.

What happens, is when the gun is fired, the gas in the case expands, pushing toward the shoulder and base of the shell, to seal the chamber and expell the bullet. As the bullet proceeds down the barrel it passes a gas port, some gas is bled off and starts pushing the operating rod (via a piston) back, starting the extraction process, This all starts happening while the bullet is still in the barrel. So you still have gas expanding in the case, pushing on the shoulder from the inside while you have the extractor starting to pull the case out. At this point the brass is quite hot and elastic. Because its being extracted it doesn't get a chance to snap back into shape like the brass out of a bolt gun.

Anyway, this all can be prevented by using the case length gage to set up your sizing die, and checking the brass after its re-sized.

 

[Vt.birdhunter]

Is it possible that a company such as BVAC would not be sizing its brass properly?

 

[dvdcrr]

I reloaded a bunch of cases for a 308. These went through my die kind of tough so I figured they would be on the big end. They would not feed/chamber into the saiga 308. However the M1a ate em and spit em out like candy, shooting MOA groups to boot! Not a hint of resistance. Made me scratch my head. Could it really be? A russian (God forbid) rifle chambered tighter than a semi-American M1a?

 

[Charlie98]

What Slam Fire said or it could also be an extremly dirty chamber

That was my first thought, too.

If you are firing steel-cased ammo, you really need to clean the chamber well, afterwards.

And until you are back to 100% feeding, I would be eyeballing the bolt lugs after every cycle before I pulled the trigger.

You also might want to check your safety bridge for a burr or other problem. One of the guys over at M14tfl had a new SAI rifle with a buggered up safety bridge that was hanging up the bolt.