Split case -- waddaya do?

[TimRB]

I read an account by someone who bought some of the Korean M2 ball ammo on Garand clips having problems with cases splitting. Since I recently bought a pile of the stuff myself but have not fired any of it yet, I'm now a little nervous.

Maybe this is a stupid question, but in general what are you supposed to do if you get a split case? If headspace checks out OK, should you discontinue firing the ammo? Is an occasional split case serious in a rifle with nominal headspace?

Tim

 

[George S.]

You may want to inspect the rounds. Use one of those magnifiying glasses with the light that you mount on a work bench. If I found a loaded round with any indication of splitting or cracking, I would use a bullet puller to remove the powder, keep the bullet and toss the case after depriming. Any cases that split after firing just go in the trash.

 

[pbhome71]

Do you know what is the head stamp of the ammo? I heard that the Korean M2 on enbloc clip is corrosive. Can anyone confirm?

Thanks,

-Pat

 

[George S.]

The stuff marked KA is supposed to be corrosive and the PS is not. I think that is part of the lot numbers on the cartons.

 

[M2 Carbine]

I had the blown case.
It's dated 1972.
I inspected the 200 more rounds that I have and found one more cracked.
I have no problem with shooting it after checking it over.
The ammo that I have that's in the Garand clips is dated from 96 to 73.
I'de guess the 90's ammo is corrosive judging from some cases being corroded.

The crack has nothing to do with the ammo being corrosive or not.
It can be seen there was a problem with the case forming or the brass.

You can see the case didn't "blow out", it was burned out, almost like with a small torch.

The cracked case can be seen once you know what to look for.

 

[QuarterBoreGunner]

Whoa. I saw 'case splitting' and automatically assumed you meant 'neck splitting' but damn, I'm amazed the case head didn't seperate on you. No damage to the firearm or shooter I take it?

 

[Jim K]

First, lengthwise splits in cases are NOT due to excess headspace. Excess headspace shows in circumferential stretch marks on the case and, at the extreme, cases parting with the front part left in the chamber. Nor are they due to the type of primer used; corrosive primers leave a corrosive salt as a result of being fired; they do not corrode the brass before firing.

The type of split shown is probably due to a flaw in the brass that was pulled through the brass during drawing. It indicates QC failures by the maker of the roll brass and in its inspection at the ammunition plant. There is no real way to detect it or do anything about it in advance except to not purchase ammunition in which it shows up. Broader splits are usually due to internal corrosion from acid left in the powder, again a failure of quality control.

Those splits rarely cause any serious damage, but sometimes there is some gas escape, a good reason to wear eye protection at all times when shooting.

Splits at the neck are usually due to season cracking in older ammunition; these rarely cause any problem and are not even noticed unless the fired case is examined.

Jim

 

[QuarterBoreGunner]

Splits at the neck are usually due to season cracking in older ammunition; these rarely cause any problem and are not even noticed unless the fired case is examined.

That's what I was thinking when I saw the thread subject. I've had plenty of rifles cartridges split the neck, and Jim is spot on. I've also had it happen due to work hardening in reloaded cases.

 

[M2 Carbine]

Today I ran the rest of that 1972 ammo through the CMP M1 I just received.

No problem.

The 200 rounds of KA 72 ammo and M1 Garand did just fine.



What Jim Keenan said.

With a 30x glass the "flaw in the brass" can be seen.

 

[Jim Watson]

That is listed as an "L-split" in an Army diagram shown in the old NRA Handloading. It is considered dangerous because it is so far back on the brass that it can vent gas through the action that a crack farther up in the side wall would not.
The only thing worse flaw of the type is an "M-split" where the casehead cracks into the primer pocket. ONE "M-split" would cause an entire production lot of ammo to be withdrawn from service.

Wear glasses, chuck any round of cheap asiatic surplus that shows a visible flaw.

Y'all be careful, now, you hear?

 

[M2 Carbine]

That's right, it sure does vent gas through the action.



I think I might have vented a little gas myself.

 

[Z_Infidel]

I'm glad I found this thread. I've had two cartridges split like that in my Enfield and have long wondered about the cause. I was reasonably sure it wasn't a headspace issue since I had it checked by a gunsmith when I bought the rifle.

Question: I still have a few boxes of the ammo left, and most of what I've already used has functioned properly. Would it be best to junk the remainder, just shoot it, or inspect every round before firing? Will a reasonable inspection reveal an existing flaw? How at risk is my rifle if more split cases are encountered?

This thread is another great example of the knowledge of the board members being of very practical use!

 

[Chipperman]

M2 carbine-- Excellent pics!

All the Korean ammo I've used so far has been in the 20 rounds cardboard boxes. Have not had any split cases.

 

[M2 Carbine]

Chipperman,
I've got a couple cases of the boxed Korean 30/06.
The overall quality looks much better than the ammo that is on the M1 clips.
I haven't tried it side by side but I'de bet the accuracy is better to.



Z_Infidel,
Once I figured out what to look for, the cracked case was easy to see with any magnifying glass, even with just my eye glasses.

I wouldn't tell you to shoot your ammo or not.
I had no fear of shooting mine after looking it over.

Yesterday I shot all the 1972.
I've seperated the rest by year and just to be on the safe side I'll inspect it before I shoot it even though I'm sure it's OK.

Strickly my OPINION, but I don't think your rifle is at much risk if the case failure is NO WORSE than this one.
I was shooting a 03A3 and some of the gas bypassed the bolt and hit me in the face with enough force to make 6 little bloody marks.

Not something you want to happen very often.