case testing

[TRG65]

I was wondering on how people might check brass in volume to see if it is in danger of case head separation.

Background:  I had a case head separate on a 9mm load.  The round was being fired in a Barsto barrel for the Glock 34.  The bottom half of the case head and concussion blew the magazine and 8 rounds out of the gun.  The extractor was gone when I examined the gun.  The total damage was a missing extractor and the top front edge of the mag was pretty damaged.  The other rounds that I've fired have shown no signs of excess pressure.  As a general rule I don't case gauge rounds because they all pass, unless I've got a primer that didn't seat correctly or a case mouth that was messed up, either of these I catch when I'm loading the mags.

The brass was mix and match that I picked up from matches or the range or that I bought from midway.  As near as I can decipher from what is left of the headstamp the case that separated was most likely from a batch of once fired I bought from midway a year and a half ago.  Since then it has probably had about 7-10 firings.

I think I just had a worn out case.  Does anybody have an easy way to check for worn out cases (volume method) or do you just replace your brass every year or at a particular number of firings?

[warpspeed]

HTR,

As cheap as once fired brass is, I shoot it and leave it.

roll sized and all

[Loves2Shoot]

Ditto with 40 and 9mm, not worth the hassle to pick it up.

[kevin c]

Don't know of any routine inspection tricks for what you are thinking of, which is incipient case head separation in a pistol case. I know that you can look for thin, shiny circumferential lines in rifle brass, which supposedly is an early sign of ICHS, due to stretching of the case with multiple firings, but I didn't think that stretching  really happened to any great degree in straight walled pistol cases. I have seen lines like I described above in 40 brass, but only in nickeled cases, and nowhere near the casehead/wall junction where case head separations in 40s rarely do occur. I've never been able to get anybody, including some folks with a lot more experience than I have, to tell me if those lines mean anything. I have not ever had a case head separation myself, but can't tell you if that is luck or because I monitor my brass and have so far shot high end loads only in brass whose history I know well ( those lines I've seen haven't caused any problems in my practice loads so far).

A couple other observations - If you are shooting a mixed bag of range brass, you really don't know what you are getting, maybe new, maybe very old and tired. Once fired brass may be cheap enough for some people to not pick up, but, no offence meant or implied, it also means that how and through what kind of chamber it got to the buyer doesn't mean much, because he won't shoot it again, and similarly, it may not matter to him how hot he loads it the second time and what his own chamber does to it because he won't be shooting it any more. BUT YOU WILL. Your 6x or 7x fired brass might be a lot more senile than you think. Any range brass I get is used only for low power factor practice loads. I recover as much of my brass as I can, and when I think that it needs to be retired, I don't leave it on the range for someone else to have a problem with. It goes to the trash or to a metal recycler.

It might be worth considering what your own chamber is like. In 40 at least, which is what I have the most experience with, unsupported chambers can be hazardous even to new brass, if the load you are using is hot rodded. Haven't heard of such in 9mm, even in Glocks, but mebbe somebody else out there has. Also, perhaps your load was too hot? Case head separation implies a problem in the brass, but in the majority of the blowups I have heard of, and in my own personal experience, it was a human error on the part of the reloader.

Just my opinion - I'll shut up now.

[TRG65]

The loads I shoot are all low pf.  Infact the particular load in question was about 133 pf.  I was using a 147 gr bullet and 3.24 grs of VV320.  It was not a hot load at least not compared to what some other people shoot.

Should a fired case before resizing be able to drop easily into a case gauge?

(Edited by HighTechRedneck at 3:17 pm on Mar. 7, 2003)

[Loves2Shoot]

I personally have never seen a case that will fit in a case guage without resizing.

[EricW]

With once-fired 9 and 40 brass running $8/1000, my days of cleaning and sorting pistol brass are coming to a rapid end.  

[kevin c]

You may be right, Erik, and it seems that there are a lot more folks thinking the same way. There sure is a lot more 9 and 40 lying around the HotShots range these days. I still police up my own brass though - old habits die hard, or perhaps I'm just a bit too anal retentive/compulsive.

It was my impression that case gauges are supposed to duplicate SAAMI minimum spec chamber dimensions so that any loaded round in that caliber that is a go in the gauge is a go in a factory standard chamber. I'd think that any chamber bigger than the minimum would leave you with a fired case that is likely expanded beyond those dimensions, and that wouldn't go into the gauge.

(Edited by kevin c at 12:28 am on Mar. 8, 2003)

[TRG65]

L2S

I actually sorted my fired non resized cases that way and had about 50% that checked out fine.  Those were the cases I shot today at an IDPA match