Reloading M1A


May 17, 2010, 11:48 AM
I had posted this in the rifle section, not realizing there was a handloading section, my mistake.

I have a new "used" M1A, was told it has less than 200 rounds through it. According by serial number it is a 2005 model year, scout squad.

I sat down to load up some rounds for it and found that my once fired brass cases, some LC, some Indian .308 were pushing 2.025-2.029 , while max is 2.015 and trim to is 2.005. My unfired round case length is running 2.005.

Is this normal to have that much case strech from one firing? I have been reloading my ARs and .45's for a while and the .308 round is new to me.

I did search and have not found any conclusive answer, your thoughts and input would be appreciated. I am concerned that there is something wrong with my chamber or timing (like I know what that is...!).


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May 17, 2010, 11:57 AM
Thought I would follow it here and answer any other questions you have. Yes, they can stretch quite a bit. You must trim every time to be safe, to not trim could cause an out of battery fire.

Be sure that you are using hard primers. The only ones I will use are CCI #34, they are military hard primers.

May 17, 2010, 12:00 PM
Thank you birddog, I will have to pick up a case trimmer, I have about 200 pounds of once fired LC 5.56 from my days in the Navy and have only be reloading a short while, so I have not ran into a case that I need to trim.....yet, but it looks like those days are over, ha ha...

Dave P
May 17, 2010, 12:00 PM
and ditch the indian cases, too.

May 17, 2010, 12:20 PM
I've never owned any Indian brass, but I don't see any reason to ditch it. The problem was the powder from my understanding with blowing guns up.

Gun, there is a PDF out there that goes a bit into loading for the M14 by a guy named Zeddiger, I think. Also, check out; it is the definitive M14 web forum, and there is plenty of reloading info there.

The M14 is someone constraining to load for, and frankly, far more complicated than loading for a bolt gun. But, it is still easily learned. Kept within certain guidlines, it is perfectly safe and fun. I know that when I did my research, I was seeing all sorts of "experts" who's claims made me think that if I reloaded for the M14, I could cause the destruction of the earth!

May 17, 2010, 12:43 PM
I have two M1A's, one Standard and one National Match. There is no mystery about loading for them, other than using the proper powder and primers.

One of the popular myths is the M1A stretches brass at a much faster rate than a bolt rifle, due to the rapid extraction of the gas operation. I did an extended test with my Standard M1A by closing the gas port and firing 100 rounds through it, functioning the rifle as a bolt action. Then I fired 100 rounds through it with the gas port open as normal. All ammunition was new LC ball. Using an RCBS Precision Mic, I found there was no difference in the amount of case stretching between the methods of firing in MY rifle.

I couldn't perform the same test with the NM, since the gas system is permanently installed in the open position by the factory.

You will have to trim the brass, but I trim all rifle brass every time it's fired and before it's reloaded. It's just part of my rifle loading routine, just like cleaning primer pockets is. Some people don't, but I do.

Glen Zediker has published some of the best information on loading for the M1A, so the suggestion for reading his material is a good one.

Hope this helps.


May 17, 2010, 12:43 PM
You are spot on Birddog and Fred, I found it Saturday night when I noticed the case lengths, here is the link to it if anyone else is curious, it really goes into great detail.

I fired off an email to Springfield to see what I get back from them. Keep coming guys, someone out there has probably had this strech, can I be the only one?

May 17, 2010, 01:25 PM

In your other post, you said of the 2.025-2.029" case length: The case length is before I resize...

The comparison of the unsized case length after firing to the max of 2.015" or 2.005" trim to length is irrelevent. You have to full length resize the brass, measure it and compare that case length to the 2.015" max length.


May 17, 2010, 02:14 PM
When I sat down to look at them I was just surprised to see a .020 to .024 increase in the case length, hence my question on what is "normal", is that not a bit much? I know the brass, wall thickness, etc all contribute, but it just seemed like alot.

I am having accuracy problems with the gun, so I am wondering what could be contributing to it.


May 17, 2010, 02:44 PM
Did you measure the brass before you fired it the first time and compare it again after firing?

I've loaded the Indian brass, and it worked just fine, so give it a try before you scrap it out.

And USSR is correct, you need to measure after sizing. Also, check and make sure you don't set the shoulder back more than about .003" when sizing, since setting it back too far will affect headspace and result in premature case head separations. I've set up a die just for my M1A's, as they both have the same headspace. I set the shoulder back .002" and get good case life from my brass.

I've achieved 5 shot 1.5" groups with both of my M1A's at 100 yards using IMR 4895 and 150 grain bullets. I figure that's not bad for a "service" rifle. The NM shoots about the same as the Standard, since both are very accurate for what they are. Of course, conditions have to be good and I have to be having a good day..........

Hope this helps.


May 17, 2010, 02:55 PM
That's awesome, 1.5", man I would pleased with that. I measured a new LC round shell case prior to shooting, it came in at 2.005, the others did too, but after firing, well, you know that story. I'll do some sizing on them tonight.

May 17, 2010, 09:23 PM
+1 to ReloaderFred. Proper sizing is important. I trim new brass before the first firing in my M1A. There is a lot of variation in new and factory brass. Once fired I check case length again and trim only those that need it. I try to set the shoulder back less than .001" or just enough to chamber easily. A headspace gauge helps with this. I also keep loads on the "light" side finding 42 grains of IMR 4895 to be the most accurate with 168 BTHP Sierra bullets and Winchestrer cases. Most of my "match prep" winchester cases have been loaded 10+ times with a neck aneallng at 6 reloadings. So far I have had no case head seperations or neck cracking with this lot of 500

May 17, 2010, 11:26 PM
It's my practice to not post loading data, but since Curator posted his, I'll just say that the load he uses is one of my favorites. It's also one of the most accurate in my M1A's. I also use that load with 150 grain bullets and that's what got me the 1 1/2" groups.

Hope this helps.


May 17, 2010, 11:39 PM
I also load 42.0 gr of IMR4895 behind 150 gr and get excellent results from it. No sense loading to the max and beating up your shoulder and gun.

I would add to get a case length gauge such as Dillon's and be sure you're not setting the shoulder back too far. Doing so can give you more case stretch and premature failure which will ruin an otherwise sunny day. :cuss:

May 18, 2010, 11:03 AM
Thanks all, I will check it out, got too busy last night and could not get to the bench.

Peter M. Eick
May 22, 2010, 07:48 PM
Just remember if you use C-34s they are magnum primers. Take that into account on your loads.

I only run C-34's in my M1A's. Maybe it is overkill but I have had no problems so why change.

May 22, 2010, 08:19 PM
I sat down to load up some rounds for it and found that my once fired brass cases, some LC, some Indian .308 were pushing 2.025-2.029 , while max is 2.015 and trim to is 2.005. My unfired round case length is running 2.005.

I earned my Distinguished with the M1a and am on my third match barrel on this SuperMatch:

I have shot up 5 gallon buckets of LC brass. Only when it was issued did I ever get to shoot new LC. Then you had to compete against the other brass thieves to get 22 cases from the pile in front of the firing line.

Those were the good ole days!:D

Anyway, I have never shot LC that was not close or did not exceed max trim length on the first resizing. The stuff grows the first time it is resized. It also grows on subsequent firings. Somewhere around five to ten reloads the stuff work hardens and I end up trimming about .001 to .002" when it stablizes. Changing the rifle or changing the sizing die makes it grow again, and I have no idea why.

I bought a Gracey then a Giraud trimmer. I can trim 88 rounds, start to finish, in about 10 minutes. So I just trim each and every reload. I trim to 2.00 plus or minus the process variation.

Always trim or check the length. Long throats will pinch the bullet and you will blow primers.

That's how I learned how important trim length was to safety. :o

May 23, 2010, 01:44 AM
Reloading for an M1A isn't any different than loading for any other semi-auto. You must FL resize, watch the case lengths and chamfer and deburr after trimming. Other than that, it's the same as loading for any rifle. Mind you, it does void your warantee.
"...must trim every time to be safe..." Um, no. Check the lengths and trim as required, for sure, but trimming every time isn't neccesary.
"...they are military hard primers..." Nope. They're nothing more than a marketing gimmick for magnum primers. Not neccesary for any battle rifle or copy of one. Been using regular primers in my real semi'd M14 for eons.
" not trim could cause an out of battery fire..." Rubbish.
"...Indian .308 were pushing 2.025-2.029..." Isn't high quality brass. Pitch 'em. It's not worth fighting low quality brass.

May 23, 2010, 07:38 AM
Those were the good ole days

No. the Good Ol' Days were when the guy on either side said that you could have the brass as he had more than he would ever need.

Reloading for an M1A isn't any different than loading for any other semi-auto
I'd also add ream out the primer pocket for uniform depth.

"...must trim every time to be safe..." Um, no.

Using the Lee Trimmer, it's just as easy to check the case in the holder and trim. If it's short enough, no problem. If it isn't it's trimmed. In the end as quick or quicker than a measurement.

Peter M. Eick
May 23, 2010, 10:57 AM
I admit that I trim every round, every time in my rifle reloads. Why not? With the powered RCBS 3 way cutter, it trims and chamfers as quickly as the powder dispenser will drop the charge. It works great.

May 25, 2010, 01:59 AM
Just as a NOTE: I am a brass case junkie, if it is bras and boxer primed I pick it up. All LC brass that has not been reloaded will be long, no matter what caliber, that is how I have found to distinguish between once fired and reloaded LC cases.


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