M1 Garand case split from a new krieger barrel

[U.S.SFC_RET]

I watched a shooter with an M1 breaking in two krieger barrels. He would shoot one round and clean the barrel, that's good because it means a cleaner shooting barrel inthe future. He showed me a split case from one of his M1 Garands that he was shooting and wanted to blame the govt '43 ammo that he was shooting. I asked him to let me look at some of the shot brass and this is what I saw.

The split firing case was split from the shoulder all of the way through to the primer. (he is one lucky fellow) The primer was a bit sunk in compared to the rest.

1. One very heavy scratch mark running along the alot of brass cases.
2. Firing pin mark seemed to raised around the firing pin as the firing pin struck the case during firing.
3. What looked like stretch marks just above the base of the brass.

I asked him if he reloaded, he said no but he wanted to blame the Ammunition since the barrels on both M1s were installed by a (very) reputable Gunsmith in the Eastern Md/Pa Region. He spoke of him as if every one knew him, I didn't and I can't recall his name.

Is it a Firing pin timing issue? Is it a New barrel Headspace issue?
Is it an Ammunition issue.
I believe that it is a headspace issue pure and simple and when You install a new barrel on an M1 Garand you have to use a pull through reamer to set the headspace on that new barrel. I am assuming this (reputable) gunsmith either mucked up a barrel or installed a bad barrel to begin with.

 

[3sixbits]

I (without seeing it) would suspect "seasoned brass". I have ctgs, factory loaded ammo from the 1920's that has split the cases from the mouth to the base. Unfired, new in the original boxes. Sounds strange? Not when we remember the drawing and annealing process involved making ctg cases. Funny what a guy can keep and accumulate in a life time of collecting this crap, ain't it? By the way, I once fired 7.62 nato in a Garand (ammo was handed to me) during a match at Camp Perry. The Nat match Garand was chambered for .30 Govt. Head space, you bet, results on the brass was rimless looking .410 cases. And a great group in the grass.

 

[U.S.SFC_RET]

Govt '43 Ammo, leastways the guy said that he had a headspace set at the house. I hate to blame the barrel but that case looked wicked. Govt ammo has thicker brass and can stand a beating. This is why I couldn't blame the case just yet.

 

[3sixbits]

Sir: the most common sign of excess headspace would be "case head separation". In this case (with a good extractor) the shoulder would be blown forward. And I'm sure if you noted a shinny ring just forward of the head you would definitely be checking headspace. I know of no other condition that would cause the kind of results you describe, than seasoned brass. I remember the DCM ammo we all bought back in the 50's much of it was for use in machine guns as it was clearly pulled down from linked. That ammo was hot, pull the trigger on that stuff in your old deer rifle when it was then well under voting age and you knew that you were going to feel it the next day. Now add a whole bunch more years and the fact, you (or he) did not reseat the bullets and what you've got in this high pressure condition with seasoned brass, sounds just like what you describe as to the condition of this brass. Lets say this barrel was a .25 cal barrel and the chamber and throat was cut to a 30 govt. This still would not cause the kind of condition you describe with good ammo. If anyone reading this does not understand what I'm conveying then you need to read "HATCHER's NOTEBOOK" and or P.O. ACKLEY "HANDBOOK FOR SHOOTERS & RELOADERS" Vol I/II.

 

[Jim K]

One common problem with WWI and WWII ammo is internal corrosion from powder that did not have the acid entirely removed due to the fast production required in war time. When this ammo lays on one side for decades, in a box, the acid eats away at the brass from inside, on one side of the case. The damage cannot be seen from the outside, so the ammunition looks good. But when the round is fired, the brass burns away along the line of corrosion, leaving what some people call a case "split" and ascribe to "seasoning." It is not, it is simply a line of brass eaten away by acid from the inside.

This should not be confused with "corroded" cases, where corrosion or verdegris is on the outside and visible, or with the use of corrosive primers, which release corrosvive salts only after firing.

This type of case failure seldom causes a problem as the rifle will commonly handle the small release of gas with no problem, but once ammunition is found to be defective, that batch should not be fired any more and should be broken down to salvage the bullets. The cases and powder are not salvageable.

Jim

 

[U.S.SFC_RET]

OK Jim I am going to take your word on it. That case split was surgical to say the least. What about the primer that was sunk in a bit? What about the firing pin protrusion after it was struck on the other cases? is that normal? The firing pin dimples looked a bit raised around the edges on some of the brass since he was firing two Garands. This prompted me to tell him to headspace the Garand that split the case. I understand what you said about WW1 and WW2 rounds and acid and all of that. Thank you.

 

[Jim Watson]

1. One very heavy scratch mark running along the alot of brass cases.

Sharp edge on his clips?

A split case back into the primer pocket is one of the most dangerous ammunition faults and is not due to headspace. If it had happened in service, that whole lot of ammo would have been rejected, per NRA.

 

[Onmilo]

Why anyone would be shooting 64 year old combat ammunition in a Kreiger barrel Match gun is beyond my comprehension!

Winchester and Federal both make factory Match loads that would be way more suitable for that type of rifle.

Spend $2000.00 or more on a match rifle and buy $5.00 a box ammo to shoot in it.

 

[Bwana John]

Why anyone would be shooting 64 year old combat ammunition in a Kreiger barrel Match gun is beyond my comprehension!

+1:banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead:

 

[10X]

A headspace problem would usually result in the base being torn from the body of the case. A too large chamber might cause a case split, but if the gunsmith was competent that wouldn't happen.

Most likely it is the old ammo. I have had shoulder splits, neck splits and partial body splits from WWI and WWII USGI ammo.
Recently I had some partial case splits from some 270 Remington ammo using a model 70. Spitting stuff in your face is a real wakeup call. I didn't know how old the ammo was, but the boxes were in good shape and the exterior looked fine. Nothing was wrong with the rifle it is a known old friend that was my Dad's. Some lots don't age well and you cannot see internal corrosion.

 

[Jim K]

Hi, US SFC,

I am not certain that my hypothesis was the cause of the problem, but it is one possibility that seems to fit, and one I have seen. Note that those acid cracks will not be simple fine cracks like split necks; they will be burned looking lines.

On the primer, I am not sure what you mean by "sunk in." Normally a primer seats on bottom of the pocket and can't go in any more. Of course, some ammo makers seated primers, especially the old round primers, a bit deeper than we are used to seeing today, but that should apply to the whole batch of ammunition, not just one case.

The firing pin protrusion can easily be checked. On an M1, it should be a minimum of .044" and a maximum of .060", though they often run more. Too great protrusion is generally no problem; the firing pin will always stop in the primer.

I am not sure about the "dimples" you mention. If you mean that some of the primer brass flowed back into the firing pin hole, that should not happen. Either the firing pin hole is too large, the firing pin tip too small or the firing pin blow is too light. The M1 does not allow the primer to flow back into the hole, since the firing pin should almost completely block the hole. Unlike some rifles, the M1 firing pin cannot be driven back into the bolt allowing a blanked primer, even if the firing pin blow is too light.

Having the rifle headspaced is a good idea; it never hurts to check the obvious, even if it doesn't seem to be the problem.

One more thought. If he had a new barrel put on, what other work did he have done? Was work done on the trigger pull, mainspring, etc.?

Jim

 

[U.S.SFC_RET]

I don't know what other work that he had done to his M1s to be honest with you. The outer appearance of the stocks gave me the impression that the M1s were rack grades and nothing else was done to the Garands other than the Barrels were replaced. I have no Idea where he got the '43 ammo but the lesson I picked up on is I won't be shooting any '43 ammo anytime soon.
Maybe You got me wrong with the firing pin thing. It's like a tiny bit of metal is flowing back around the firing pin at impact of the firing pin. this was only found at the split casing and appx 50% of other spent cases, he had 2 M1s. I also think he wiped down the casing before he showed me the split casing but the casing was split straight down as if you cut it with a fine torch from the mid point of the shoulder all of the way down into the primer pocket area in a very, very straight line. Like I said before I thought I seen some of his brass stretch above the base line/solid base area. Brass was brighter, too bright for my taste. I wish I had a micrometer to mike the brass then because definitely intrigued by the krieger barrel.
Very strong possibility of bad '43 ammo, wierd from my first experience seeing it.

 

[U.S.SFC_RET]

The original M1 owner contacted me through THR. the fault lies with old ammunition. Not with the gunsmith and not with headspace. As the firer stated the gunsmith is very reputable and respectable in his business.

 

[nbkky71]

I once had a case let go on me when I was firing my '03 Springfield. The ammo was '69 Greek HXP M2 ball.

It scared the bejesus out of me and gave me a nice love-tap on my forehead from the escaping gas. Caught a little brass on my eye protection. Just another reason to wear it. I'm sure I would have lost my vision if I wasn't wearing any.

Anyway, I had the rifle checked out by my gun-plumber and everything was fine: chamber was fine and headspace was good. I checked with the CMP about the lot of ammo and there were no reported problems. None of the ammo showed any signs of corrosion.

Sometimes you just have a bad piece of brass...

 

[Jim K]

Nbkky71, I agree. That looks like a failure due to a flaw in the brass strip. Not good quality control, but even a close examination might not have caught it Glad to hear you weren't hurt, and a good lesson to others to keep that eye protection on.

That split does show a weakness in the M1903 with its cone breech. A Mauser 98 would have handled the situation better, and with something like the Remington 700 you probably would never have known anything odd happened.

Jim

 

[bobsmith]

Why not just check the headspace on the gun with a set of gages? Does the same problem happen with newer ammo?

 

[lmccrock]

Just thinking out loud - I wonder if the "gov't '43 ammo" was really remanufactured by Talon or another commercial source?

Lee

 

[U.S.SFC_RET]

lmccrock What the firer explained to me, (he discovered this thread and PM'd me) was that he had some '43 ammunition Govt. He cleaned the rounds because he noticed the corrosion. Black spots remained on the cases. AP round (black tipped).
Important to note that when in doubt about shooting old ammunition is there will not always be corrosion on the outside but in his case there was. He just cleaned it off.

 

[Magnumite]

If the split case is still available, couldn't it just be peeled open and look for signs of corrosion and verify that is the source of the problem? They should still be there despite being fired.