Ok, I know the issue of .40S&W KB's have been beaten to death. I was thinking about this the other day, especially concerning Glocks in .40 and here is what I was thinking. If a particular individual round (say round 24 of a 50 round box) is going to KB in a firearm due to (state reason here), what would you want to happen? Knowing that force typically goes the path of least resistance, having a less supported chamber seems like a good thing. With the increasing pressure in the round, the pressure is going to expand brass to the ends of the chamber. Assuming the bullet has not left the muzzel, that 6 o'clock gap would be a good place for the case to rupture. The resulting brass fragments and hot gas jet going down the magazine well. I've seen in 1911's where the fragments and gas has punctured and set off the next round in the magazine while the magazine is being forced out of the well. In this case the powder just burned out through the hole in the top of the brass Now if you compare this to a fully supported environment. The pressure is essentially bottled, like a pipe bomb. This seems like it would exibit more force on the barrel itself. This would cause the metal of the barrel to rupture and the case to seperate and blow backwards. The main exits to the barrel are going to be forward with the bullet leaving, and aft with the shell (pieces) leaving. Now from my perspective, I do not want much of the force coming backwards towards my face, eyes and teeth. My doctor has assured me that most, if not all body parts do not grow back. (Mostly after I dislocated my arm, I asked him if we could amputate and let it grow back, he said no.) Given that a major KB is going to tear the barrel open from chamber end and possible shots parts backward, would you want extra force vented down through the mag well? In either case the gun is destroyed. Now the next question is that given a choice between a minor KB that might be seen as a case rupture in a Glock, or as being contained in the barrel with no case rupture and increased recoil, for example an HK where "That one felt weird"). Which would be preferred? The case rupture where the firearm is damaged a little, or the contained one that potentially weakens the chamber and barrel of the example HK, and could lead to more major damage later? Do you think a Glock could survive multiple Minor KB's as a result of the chamber support being less than a more supported firearm that might rupture due to increased metal fatigue? I was just thinking about this while working on an HPLC detector where the flow cell gasket had failed. My brain was on pressure mode.