Originally posted by philkryder
Sorry for misinterpreting what you had written -
Regarding whether the cause was out of battery or overpressure:
We know that there were signs of overpressure per your post.
We also know that other rounds in this batch showed over pressure - again per your post.
We also know that Glocks do not fully support the case - per your references and many others.
We also know from your photos that the case failure occured ONLY in the unsupported area and not all the way around the case.
What I don't know is why you go from the above data to your opinion that
"...it was most likely a slight out-of-battery condition."
I will restate my reasons for disbelief in
"out of battery experiences" -
1) Though the trigger on a glock CAN activate the striker when the barrel is pushed slightly down and back, THE BREECH IS STILL TIGHT against the barrel and bullet.
2) all high speed photos of pistol bullets, that I have seen exiting a barrel have thus far always shown the bullet exiting the barrel BEFORE the slide-barrel begins to move relative to the frame. Any contrary photo would be very welcome.
Regarding whether to use Dean Speir's definition of KB rather than Walter's
I appreciate the argument that since Dean coined the term, it should mean exactly what he meant it to mean (sort of like the Cheshire cat in Alice)...
But, I also appreciate that language evolves, and I think that Walter was attempting to draw a clarifing distinction between different types of failures.
I can understand the confusion. Way back when I wrote up the original description (over 2 years ago, although there were a few recent additions/edits, it is mostly what I wrote the day it happened), I simply indicated all those items I thought might be involved. In the (considerable) intervening time, I have listened to and tested other ideas. Dean pointed out that "reading" primers was not a reliable measure of pressure. I originally balked at this, but it is a good point -- I was comparing primers of different, unknown brands. If I had reloaded the ammunition myself, and used the same brand and batch of primers (and shells, and slugs, etc.) then I would have a handle on more variables. But that is not the situation -- different primers, cases, and powders were all involved, and the primers that appeared more flattened may be softer primers. So that is just one data point in the analysis. I did not know the G19 could fire without being fully in battery, but testing shows I can move the slide a little, perhaps 3/32" (not exactly "tight against the barrel"), which I think may be enough to allow the case to set back slightly and blow out near the rim, as in the photos. Newer Glocks apparently will not do this, I'm told, and I have new parts from Glock to install to (hopefully) remedy this. Yours may not do this, but mine can.
So what do I think happened? I think it was the cheap plated slugs (which appeared to be jacketed, but I got fooled), which were slightly irregular, may have shaved off just a bit of metal into the chamber neck area and reduced my headspace. And/or the cases might have been slightly oversized. And the round let the slide close enough to discharge, but not quite enough to go to "full lockup" -- maybe 1/16th short -- and this -- possible combined with a slightly hotter charge -- allowed the slide to move back slightly more at discharge, and to blow out the side of the case in the unsupported area. It's just my theory, but I have had a long time to look at all the evidence, and I think it is the most probable cause. I may be wrong, but it has never had a problem with factory loads, and I have fired well over 1,000 rds (of white box Win 115 gr solids) in IPSC matches since then, with no changes other than replacing the damaged parts, so I have confidence in it, although I now know about and have received all the Glock "upgrade" parts, so these will go in before I do much more shooting.
The bottom line to all of this: you can parse my words, and others can come up with creative new definitions of what a kB! really is, but that's just talk. It doesn't solve anything. What is productive is if people do their homework and check to see if their Glocks need the upgrade, and get it done if they qualify. And they can check to see if theirs can discharge with the slide set back over 1/16" or so. And they should avoid lead or plated slugs, Federal ammo (at least for 9mm and .40), and reloads (unless they are *very* experienced and can control tolerances quite well). Maybe those precautions are not necessary with the new ones, and maybe not if you put on a better barrel.
I'd like to see people get the word, because Glock has not done a recall and NEVER tried to get the word out that people they need this "upgrade". I didn't know. I had NO idea this was possible (although I have seen perhaps 100 or more notices about Remington safeties and Ruger SA safety upgrades). The precise reason it happened is not certain. How to keep it from happening
is pretty well known. So the productive focus is on getting the word out to other Glock owners rather than (as it happens) trying to correct people on different boards who want to reintepret what happened as being something different, or to try to redefine what a kB! as something else, or to say there is nothing to worry about -- that rubs the wrong way. (The language here is not "evolving", it is being misused, hijacking a term to exclude events which it specifically includes. And I don't need a high-speed camera to tell me it didn't stay locked up long enough, and it isn't supposed to blow pieces out in your hand and leave me feeling like I forgot to let go of a firecracker. That was some pretty powerful "contrary evidence" that it didn't stay locked up long enough.)
But the message
is to pay attention and stay safe, since Glock refused to recall the affected pistols, and just isn't getting the word out. What happened, happened. If any of you guys need the "upgrade", get it (go to the web site I listed a few days ago in a prior post for details) -- and tell Glock that responsible corporations get the word out to their customers BEFORE they have a catastrophic event, not after. Let them know what you think of their policy of saving a few bucks by calling a recall situation an "upgrade" to prevent it from blow pieces out in your hand and disabling itself in the process.