I had an m&p kaboom with tula .40.
The gun was undamaged. Case blew out the back, similar to the casing shown in post 3 by bret, but it split.
My only kaboom was a 45 ACP in a Wilson Combat 1911.I've seen a few pistols of all makes go kaboom over the years.
I was on an email list for Glock owners prior to 2000 and .40 kabooms were a thing then too. I recall 180gr being the alleged source of most, if not all, of the kabooms.
The assumption was 180gr was on the ragged edge of safety from a pressure level standpoint and the Glocks .40's back then had gaping chambers compared to other .40 pistols on the market.
Never owned one, but it was interesting to pull a 22/23 barrel out and watch a factory .40 roll around in it versus doing the same with a 17/19 from the same time frame considering both cartridges operated at roughly the same pressure.
Administrative reloads were brought up as a cause back then too. I assume other calibers exhibit similar characteristics, but one of the gun magazines published a chart on .40 seating depths vs. Pressure (can't recall if it was actually measured or if it was a program that calculated) and it didn't take much "set back" to get the pressure through the roof.
Last edited by jsbhike; 02-09-19 at 07:55.
I took my 9mm Masterpiece Arms Defender shooting last weekend. FYI, it's actually one of the most accurate pistols that I've ever shot. Anyway, I had seen a video on YouTube of a guy bump firing one, so I decided to see if I could do the same with mine. It bumped fired pretty well. However, it cycled so fast that it sounded more like one loud continuous bang than a fast string of bangs. When we were done I picked up my brass and found a few that I fired out of battery.
Fortunately, the cases contained the pressure. Needless to say, I won't press my luck by bump firing it again.
I recall my Police Academy we fired Atlanta Arms lead round nose 9mm in our S&W 5906's. Didn't have any KB's, though.
Most of the guns ran really well, too. Maybe one or two bad apples if I recall.
My opinion of the gun was far higher at the end than it was at the beginning.
The construction of 40 brass has also gradually been improved since inception of the cartridge.
Early Winchester cases had little to no radius joining the inner wall of the case to the head. I would commonly find indications of the wall tearing away from the head of the case. Headstamp is WINCHESTER 40 S&W. Newer brass marked WIN 40 S&W has better construction.
Other ammo makers had some issues too but the Winchesters were the ones I found most often.
Here is photo of the inside of an old-style Winchester case that has started tearing:
Attachment 55959
The crack is large enough that a narrow strip of aluminum foil could fit into the gap.
Not the vaguest notion of how many times my 9mm brass has been thru' the press, tho' I have quite a lot of it, so the joy is spread around.
How many reloadings were supposed to be involved in the .40 kabooms? I've avoided them for this and other reasons.
Moon
NRA Life Member and Certified Instructor
Glock Certified Armorer
Admitted New York State Bar 1994
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