Glock 20 blowup:
My 20 ka-boom happened 10 years ago, IIRC--at any rate, it was the day that sick Willy proclaimed that "...(he)-did-NOT-have-sex-with-THAT-woman." Arguably, it was the first 20 ka-boom in the US; I'd had it on order and picked it up a month earlier, in December, when Bill's Gun Shop got the first shipment in.
FWIW, this was my third Glock: I'd started with a 17L (used in club competition) and bought a 19 as well for SD and home defense. I had loaded 1000s of 9mm lead reloads for these guns. It was also about the time that reports of Glock ka-booms had finally made it into the press--not much Internet chat in the early-mid Nineties, remember--and speculation for the reasons was mounting. The St. Paul PD armorer I spoke to about it (they were one of the first PDs to adopt a Glock) had heard of them in the PDs, and it was his informed opinion they occurred because of squib loads, typically in PD practice ammo; factory rounds or reloads--didn't matter.
This was the third range visit; in the preceding two, about 200 rounds of factory TMJs were shot through it to burnish the barrel. At about round 250, I started loading my standard 10mm reloads I had developed for use in my Springfield Armory Omega and my 1006--basically, a softball load that barely made Major: starline brass, WLP, 4.9 gr. of 231, under a 200-gr. LSWC. Out of the 6" Omega, they ran about 920 or so. These rounds had been loaded 'some time' before, on a Lee Pro 1000, and I had built 1000s of them and never had a problem with loading errors or with shooting them in the Omega (which also has a polygonal barrel).
In the midst of a 'measured' rapid fire drill, at about round 283, I suddenly felt a stinging sensation in my shooting / right hand--and then I noticed the slide was missing from the pistol. As I looked at my chest and stomach to see if it was stuck there, the rangemaster came running in and ordered a cease fire. I looked up to see him and others peering around the partitions.
It turned out that the slide had launched itself off the pistol over my left shoulder and traveled about six to eight feet back to hit the sheet metal cover over the ventilation system, causing a loud clank that got everyone's attention.
The guy two stalls down was an MD, and he examined my right hand--other than the sensation of a bad sprain on my index / trigger finger, and a small blood blister forming, there appeared to be no injury.
Meanwhile, someone else had retreived the slide. It was significantly twisted up, really noticably distorted, and the barrel had split at about the 4:00 position from the breech forward. The receiver was undistorted, but rails had been torn off it and parts were missing.
See this picture.
At any rate, the experience did tend to ruin the day.
I called Glock the next day to report this, and all I got was a "gee, I'm glad you weren't more seriously hurt" comment from the receptionist; not even a transfer to Customer Service.
I next contacted Winchester, and they requested I send them the parts and the remaining ammo. I did this, and eventually I got a written report and the parts back.
They'd straightened the slide enough to remove the barrel (how it looks in that photo), and disassembled the remaining ammo and analyzed the charge. For the ammo, they typically found about .1 to .2 grain less than the stated recipe (I'll bet their scale is more accurate than my Lee balance beam), and that the rounds conformed in LOA, etc., etc. to accepted (re)loading practices. They did conclude that it was a massive overpressure incident, or words to that effect, and wrote a truly masterful letter of CYA dodging-and-weaving that covered all manufacturers concerned.
So, could it have been a double-charged case / reloading error? Yes; I can't prove it was not. However, I strongly doubt that, and no evidence of a squib-followed-by-a-shot-exists. The barrel split, period. Personally, I buy into the polygonal rifling / leading issues.
I'd like to believe Glocks have evolved and been improved. The comments I read today focus much more on the unsupported-chamber issues. At any rate, the incident soured me on shooting Glocks--so I sold the other two and went on to enjoying 1911s.
Personally, I would not shoot reloads in a Glock of any date and of any caliber without replacing the barrel with an aftermarket one designed for better chamber support and with conventional rifling. But that's just me.
Jim H.