Bad brass? Lake City 2011?

  • 1.6K Views
  • Last Post 21 April 2015
Cary Gunn posted this 20 April 2015

 Anyone had any problems with Lake City 2011 7.62x51mm NATO brass? 

I've found half a dozen or more cases from a recent reloading run displaying cracks or splits across the body of the case, just below the shoulder and/or 3/8” or so above the extractor groove.

These cases were purchased over the internet several months ago, and I'm just getting around to loading them.

 I spotted the hairline cracks after full-length sizing the cases on what was to have been my 1st loading of them.  Haven't fired any yet, thanks God.  And, needless to say, I won't fire any, or load anymore, until I find out what's going on.

Thus far, I've seen the problem only on cases headstamped “LC 11.” The case heads also, obviously, bear the NATO circled-cross.

"LC 10” and “LC 09” NATO-marked cases, purchased from the same source, haven't shown any problems. 

Also,  a bunch of cases stamped “LC LR 11” show no cracks or other problems.  It's my understanding these “LC LR” cases, which, by the way, lack the NATO mark, are the current equivalent of military “match” or sniper ammo. The “LR” in the headstamp may mean “Long Range,” or so I've read.

Anyway, I'd be interested to learn if anyone else has encountered cracks or splits below the shoulder or above the base on “LC 11” NATO-stamped 7.62x51mm brass.   If there's a wide-spread problem with that particular brass, the sooner it's identified the safer we'll be.

Lemme know,

-- Cary Gunn -- 

Attached Files

Order By: Standard | Newest | Votes
Longone posted this 20 April 2015

Cary,

Make up a piece of wire, (mechanics wire is fine) with a 90* bend about 1/8' from the end and insert it into the case neck with it making contact with the inside of the case wall. While inserting the wire feel for “low” spots in the case wall.

Because it has the Nato cross it could have been fire in something that has a large chamber (machine gun) and the cracks you are describing is a result of case stretch better known as incipient case separation.

If you do find cases that you can feel irregularities in the case wall thickness where you describe, I would suggest creating a scrap brass collection and NOT firing these cases.

The “LR” on a 7.62x51 case is indeed a Long Range designation and was normally loaded with a 175 Sierra MK bullet and RL-15 powder. There was a large amount of that load that was dismantled and the brass was sold.

Longone

Attached Files

Cary Gunn posted this 20 April 2015

 Thanks Long,

I think you're correct about the bad brass having been fired in something with a “large” chamber. 

Much of the stuff is dented, scratched and scarred, and measures a ridiculous 2.033” long.  Must have been stretched and expanded, big time, in sloppy machine-gun chambers, then run over with a deuce-and-a-half, or whatever the modern military calls their current freight conveyance.   When I was behind the wheel, it was the  “deuce-and-a-half” (2 1/2-ton general-purpose truck), but that was back so long ago you could still see the rosey dawn of the internal-combustion  engine. 

Your suggestion to scrap the brass is a good one.  My penurious nature disapproves of the loss, but I'd rather lose some brass than lose an eye or other body part.

If I remember correctly, the internet source I bought the brass from mentioned much of it would likely have been fired in machine guns, but I thought a simple full-length resize would take care of that issue...didn't take into consideration the machine gun chambers might be larger than your average terrorist's pecker.

Live and learn, I guess.

Thanks again for the second opinion.

Happy trails,

-- Cary Gunn --

Attached Files

Wineman posted this 21 April 2015

The LC 11 5.56 NATO brass is reported on the internet to have issues. I have 1,000 and after a couple of loadings, no problems yet. I am not of the 25 grains of medium burn rate powder and 77-80 grain bullet school but that kind of treatment really smacks those small cases in the AR. The last years of LC 69 30-06 may be underpowered but the brass is good stuff. I have found early 60's HXP 30-06 to need an anneal after a couple of firings or the cracking sets in.

Dave

Attached Files

Dale53 posted this 21 April 2015

Cary; I have a bit of experience “way back when” with machine guns in .30 caliber. The problem is not so much “large chambers” but some of the machine guns had adjustable headspace. If it was incorrectly adjusted, then the brass would/could stretch and produce a interior ring above the head (incipient head separation). It can be very dangerous if the head separates and dumps 50,000 psi into the gun's action. Not a good thing.

If you must use the brass, then the suggestion to make a wire hook, insert in the case mouth and see if you can feel the circular depression in the wall of the case indicating a possible “incipient case head separation” and destroy those cases.

Just a thought or two...

FWIW Dale53

Attached Files

Longone posted this 21 April 2015

Dale, Good points, also you must consider the heat factor. That barrel (chamber) is pretty warm and when you rip a cartridge that is trying to seal itself against the chamber walls out of that hot chamber the tendency is to stretch the case. It has found a home and isn't happy about being removed from it under those circumstances.

Longone

Attached Files

Cary Gunn posted this 21 April 2015

 Thanks, again, gents.

I've learned something from each of  ya.

Happy trails,

-- Cary Gunn --

Attached Files

358156hp posted this 21 April 2015

Longone wrote: Dale, Good points, also you must consider the heat factor. That barrel (chamber) is pretty warm and when you rip a cartridge that is trying to seal itself against the chamber walls out of that hot chamber the tendency is to stretch the case. It has found a home and isn't happy about being removed from it under those circumstances.

Longone Longone is completely correct. MG brass often has the shoulders blown forward under these circumstances because the case is still pressurized, and trying to expand as it's being ejected. I once got into a lot of 308 brass that was sold to me sized, trimmed, and ready to load. However every piece of it cracked on the first firing, or at least the first two times I tried it in my rifle. At that point I tossed every bit of it in the scrap bucket. This stuff was really bad.

Attached Files

Close