At the range I go to, there is a display case with a couple of S&W N-frame revolvers and a bull-strong Ruger Blackhawk. All have FULLY-SUPPORTED chambers--and all experienced true kB! events--topstraps are curled upward or broken, cylinders are broken, etc. Little tags identify the cause for each: TRIPLE charge, wrong powder, and wrong bullet. Add occluded barrel (which really encompasses "wrong bullet") and you have the Usual Suspects for TRUE kB! events--excessive pressure. I've seen dramatic case failures when a 9mm cartridge is fired in a .40 Glock (don't ask!). Guess what? NO DAMAGE to the gun! WalterGA was right in this matter, as he so often was on other matters.