[rvr350]

I took a new to me sai m1a to the range. Rifle is lubed, immediately the 2nd round i have a ftf (last rd extracted, but no new round chambered). All i had was a click when i pulled trigger. It was about every 10 rd or so. I was shooting 40.5 gr imr 4064 with a 150 hpbt.

I then switched to another relatively mild load, and i had quite a few stuck fired case that require a hammer tap to move the op rod back. The gas plug was tight the whole time.

I noticed spent brass has more soot than usual, these loads were fine on my m1 308, fwiw. I will spend some time deep clean the chamber. Not sure the mag could be the culprit (cmi 10 rd)

Any advice is much appreciated.

 

[Capona]

Shoot commercial Ammo, if the issue goes away its your loads.

I took a new to me sai m1a to the range. Rifle is lubed, immediately the 2nd round i have a ftf (last rd extracted, but no new round chambered). All i had was a click when i pulled trigger. It was about every 10 rd or so. I was shooting 40.5 gr imr 4064 with a 150 hpbt.

I then switched to another relatively mild load, and i had quite a few stuck fired case that require a hammer tap to move the op rod back. The gas plug was tight the whole time.

I noticed spent brass has more soot than usual, these loads were fine on my m1 308, fwiw. I will spend some time deep clean the chamber. Not sure the mag could be the culprit (cmi 10 rd)

Any advice is much appreciated.

 

[Instructor]

The same ammunition working OK in the M1 Garand/308 does not necessarily mean that it will also work in another 308 chamber as it should. Do you have measurements of the fired cases from both rifles?? Don't suggest a Wilson type case gauge for you need to know some hard numbers from base of case to datum line on the fired case, chamber dimensions. Would also check on the distance from ogive to lands and grooves of both rifles to see if there is major difference. Once you determine if there is a difference you can reload accordingly for each rifle. Just a suggestion.

 

[KurtC]

Your loads are too light. The bolt isn't coming back far enough to pick up another cartridge. A 150 grain bullet usually takes about 44 grains of 4064 for reliable operation.

The soot on the fired case is because the low powder charge did not expand the neck enough to seal it in the chamber.

The M14 was designed for full power loads. You just have to pay attention not to go overboard with port pressure.

 

[rvr350]

Your loads are too light. The bolt isn't coming back far enough to pick up another cartridge. A 150 grain bullet usually takes about 44 grains of 4064 for reliable operation.

The soot on the fired case is because the low powder charge did not expand the neck enough to seal it in the chamber.

The M14 was designed for full power loads. You just have to pay attention not to go overboard with port pressure.

I think you hit both issues right on. I found the same charge gives me 1/10 ftf on a 145 gr bullets, and about 1/3 on a 155 gr bullet. I would expect the opposite. I will up the charges, clean the chamber and see how it goes.

But other than that, at a 100 yd, grouping was pretty decent at 2" using my tired eyes on iron sight.

 

[.49652]

How hard is it to pull back on the op rod? A new to you M1A might have a heavy spring in there that is unknown to you. My rifle cycles 42 grains of 4064 with 150 gr. bullets fine.

I started out with 39 grains of 4064 and ladder'ed up to 43 gr. and settled on 42gr. as my magic loading. Rifle shot them all no problem.

 

[wiz1997]

The extraction issue could be due to a dirty chamber or the reloaded brass may need to be sized with a small base die.

You mentioned the rifle was new to you, any idea of its year of manufacture or round count?

Newer M1A's have a tighter chamber than the earlier ones.

I had similar issues when I first started using my reloads in my 2012 Scout.

Giving the chamber a real good scrubbing helped but still was having to bang the op rod againt the edge of the shooting bench to get the spent brass out.

After some searching here on this forum, I decided to get a small base die to use during the re-sizing process.

Haven't had a failure to extract since.

 

[gumby]

While you're at it, disassemble and clean your gas chamber / piston. Dirty gas chambers will cause a number of difficulties......BGRIN1

 

[rvr350]

Year 2006 manufacture. I swapped the gas system out with a unitized one, left the op rod piston alone, has a sadlak nm op spring guide. I think the whole gas system was pretty spotless.

I don't have any commercial ammo, and i only have 1 set of rcbs fl 308 dies set. Is there anyway i could "semi" neck sizing it?

 

[rvr350]

How hard is it to pull back on the op rod? A new to you M1A might have a heavy spring in there that is unknown to you. My rifle cycles 42 grains of 4064 with 150 gr. bullets fine.

I started out with 39 grains of 4064 and ladder'ed up to 43 gr. and settled on 42gr. as my magic loading. Rifle shot them all no problem.

For the stuck cases, i had to use a small range hammer and give it a few small tap(nothing too violent). But it was stuck, jerking it didn't move.

I will try a 42 gr 4064 and report back. I always try to load light and as accurate as needed. I assumed the similarity of the m1 and m1a gas system doesn't require a change in loading spec.

 

[rvr350]

Do you guys think the ftf (happened with 40.5 4064 with 145 gr hpbt) and the stuck cases (same charge, 155 hpbt) are linked together?

It seems to me if my light load is causing issues, my spent round would still be in the chamber, and using the op rod to clear the round manually shouldn't require a hammer.

I could see how a light load is able to push the spent round away, but unable to pick up a new round...

 

[SGT John SWF]

Year 2006 manufacture. I swapped the gas system out with a unitized one, left the op rod piston alone, has a sadlak nm op spring guide. I think the whole gas system was pretty spotless.

I don't have any commercial ammo, and i only have 1 set of rcbs fl 308 dies set. Is there anyway i could "semi" neck sizing it?

Do all your Hand Loads fit in a Wilson (or who ever's) Case Gauge?

With the RCBS Dies if you follow their directions the shoulder will not be set back correctly.

I had the same issues as you until I...
A) got a case gauge and..
B) set the die down far enough to size the case correctly.

As far as changing the gas system there is another person here who fixed something that was not broken and had issues.

Do one thing at a time.

 

[.49652]

John beat me to it. Did ya check the gas hole alignment with the cylinder? That's a must before anything else. You won't be the first one that's had a misaligned gas system, as I hold my head down in shame..................LOL!!

 

[KurtC]

I use RCBS Competition FL dies. You need to screw the sizing die down till it touches the shell plate, then go another 1/4 turn. Never had an issue, and I load for about a dozen different M1A's.

 

[SGT John SWF]

I use RCBS Competition FL dies. You need to screw the sizing die down till it touches the shell plate, then go another 1/4 turn. Never had an issue, and I load for about a dozen different M1A's.

Perhaps the take a bit more care when they produce the Competition Dies.
I am using a SB Die (not that it should matter) and my next step was going to be removing some metal from the bottom of the Die to get down to where I needed it to be. Perhaps it is something to do with the Press.
I am using a Redding Boss with the RCBS Die.
All I know id I had to crank it down way more than 1/4 turn to get the sized cases to fit my Case Gauge.

I don't know it the OP has this problem.
I guess we will see.

 

[KurtC]

All I know id I had to crank it down way more than 1/4 turn to get the sized cases to fit my Case Gauge.

That's why I don't own a case gauge. RNGR2 I've loaded thousands of rounds for over a dozen M1A's, Socoms thru National Match, including lots of USGI barrels. Never had a problem in any rifle.

Always the same recipe. Full length size with RCBS Competition dies, 43 grains of 4064 under a 175 or 168 SMK loaded out to 2.815. (42.5 grains in an LC case).

 

[SGT John SWF]

I should have bought a Redding die.

 

[POLACK]

load all your ammo used in military rifles to 308 garand specs
http://bearblain.com/Service Rifle Loadings.html
http://www.brownells.com/reloading/...e-case-length-headspace-gauges-prod55081.aspx

 

[.49652]

According to Bearblain 42gr. of IMR4064 or IMR4895 pushing a 150 gr. head is a good load. Works great for me.

 

[Warthogge]

Once I started using Redding SB dies, my extraction problems ceased. Be sure to lube well during resizing to prevent stuck cases.