I have shot over 69,000 rounds in my G19 and have had no problems.
However, I have witnessed issues with .40 and .357 sig glocks.
I think if one examines the process by which these pistols were designed and marketed, you could easily see where Glock has created some problems for themselves.
I will stick with 9 or 45, the way Gaston meant for them to be.
I believe the Kb that you are trying to discuss hear would fit this description :
spiral crack on frame starting on right side of pistol leading clockwise descending the grip; most of chamber gone from the barrel; ejected magazine; slide release and magazine release gone; slide stuck on frame rails that have been bent upwards; -- THis was with factory ammo.
I was standing about 12 feet away and got hit in the eye by a piece of metal (I think part of the chamber).
Wiley X sent me a few pairs of glasses for my testimonial.
Next time you have a pair of calipers, measure the chamber support on the .40 and the 9mm barrel; then ask yourself which one has to standup to more pressure.