Weird case failure.

[fltbed]

I have a question for you all. The more I think about it the more I think my case sizer is squeezing my brass too much. The above post about  both cases having "Glock bulge" made me look at my resized cases a little closer. In the pic above there is no case bulge on the case to the left. It has been sized and the case wall actually is narrower than the case head. It appears as a bulge in the pic but in fact it is not. I wonder if working the brass too much over a few loadings could have caused the case failure like I had?

What do your calipers say?

That case on the left defiantly looks bulged.  My resized cases look nothing like that.

Jeff

[Geeman]

First, the case head didn't separate and reassemble, unless you did clean the case after you took the inside view shot.  I had a total case head failure and EVERYTHING was covered in soot.  The magazine, the action, the remnants of the case, and even my hand where there was any gap the soot could get through.  Even left a stripe on the trigger finger where the trigger safety let the gasses through. 

Photos of brass often show reflections that look like something else.  The case on the left looks like it might have been smiled, of smiled previously.  Like I say, Photos can lie.

I believe you had an over pressure event.  I believe that over brass failure.  The brass held together rather than tore in your photo.  My mind is still trying to comprehend how it could be that close to letting go and still not rip loose.

In my reloading practice, I ONLY use powder that the charge fills the case more than half way.  If I were to try to add the second charge there would be powder everywhere.  Its just one of my ways of keeping myself safe.  Trailboss powder is a bulky fast burning powder that works great for squib loads, if desired.  I'm just mentioning for consideration.

I'm convinced that my kaboom was caused by over springy PPU brass that would rebound after sizing/crimping and not hold the bullet tightly enough.  It moved back, my loading was warm already, and the result was a case failure.  Lesson learned.  No more PPU brass in my reloading program, and I push the bullet into the bench on a few reloaded rounds to make sure they don't move, especially if I think the bullet seated too easily. 

Greg

[Pumpkinheaver]

The more I think about this the more I think I will just discard all the older Winchester brass I have. There is zero possability of a double charge. I am very careful and visually inspect every round of every tray of charged brass. I believe I had some bullet setback due to work hardened (springy) old brass that caused a pressure spike. As you can see in the original post the case in question is severely bulged and this has never occurred with this load before.

[sep]

The more I think about this the more I think I will just discard all the older Winchester brass I have. There is zero possability of a double charge. I am very careful and visually inspect every round of every tray of charged brass. I believe I had some bullet setback due to work hardened (springy) old brass that caused a pressure spike. As you can see in the original post the case in question is severely bulged and this has never occurred with this load before.

Bullet setback would definitely increase the pressure. Any idea how many times that group of brass had been reloaded? 

[se3388]

Good thing it all turned out ok, in my 40 yrs of reloading I believe that is the first time I have seen that myself. I shoot a Delta Elite and a Wyoming Arms parker 10mm as well as a Buckeye Sports Ruger 10mm/38-40.

Steve.........

[Pumpkinheaver]

I have fired 300 more of these loads since this failure. As stated above I threw away all of the old Winchester brass I had. There have been no further issues.

[DM1906]

Revisiting an incident experienced a couple years ago. Weird, but not so strange, now.

I have a friend (not one of those stories) who had a problem with some 10mm handloads. His pistol is a XL steel frame, Heavy Duty, boat anchor (LAR .45WM), he had converted to fire 10mm. Some of the rounds he loaded were blowing at the base, near the extraction groove, with some bulging evident. He just determined that his "ridiculously expensive" conversion barrel lacked sufficient support to fire, what he thought (recalled) was, 11 gr BD with 180 gr FP bullets (appeared to be X-Treme, which are simply fine at that load). He decided he wouldn't mess with them, and gave me a box with the few-hundred rounds he had remaining. I separated them by headstamp (FC, SL, Winchester, Norma, PMC, Hornady, Midway), inspected and fired a few of each in my RBH (no risk with blow-outs). Nothing remarkable. They "felt like" normal, mid-range loads, scooting along about 1220 FPS (the FC cases were much higher, but don't relate to this). I did the same with the G20 with LWD barrel (single-shot, no mag), and had a mild blow-out (not quite to the level of a KB!), then another. Both were Winchester cases, and the rounds dropped 3-400 FPS, but nothing was immediately evident. Packed it all up and headed to the lab. Close inspection was revealing. All but the Winchester cases were completely normal, well-loaded rounds. 10.4 gr BD, 180 gr X-Treme plated FP, 1.250". Otherwise, a typical target load. Closer inspection revealed the Winchester cases that blew out, had a separation at the forward, inner dia. of the extraction groove crease, approximately 1/4 the circumference. 2 of the rounds fired in the Ruger had the same, but went unnoticed (fired and felt the same as the rounds that didn't blow). A VERY close inspection revealed some of the unfired rounds had the same separation, meaning they were loaded that way, and only the Winchester cases. I find out later, the cases were purchased as once-fired and sized in a pass-through die (retail purchase from a respected source). This explained the "hidden" separations on the unfired rounds. Most of the suspect rounds also had an "ironed out" smile that couldn't be seen by simply looking. I used a wax-contact-roll method to transfer the case surface impression of the unfired cases. It stood out like a sore thumb. Although you don't think you see a smile on those cases, that is exactly what is there. Photographic lighting, among other methods, can reveal what you won't normally see. Only one of my unfired cases was immediately evident, while the rest passed a typical visual inspection without any suspicion. That one round wasn't initially selected for inspection or firing. Had I seen it beforehand, this would have unfolded very differently. I still have that box of rounds, including the failed/defective cases, somewhere.