TexasCHLforum.com

after multiple chamberings, with the bullet nose impacting the feed ramp, the bullet can be driven deeper into the casing resulting in "bullet set back". This reduses the volume of dead space in the casing necessary to handle the pressure developed prior to expulsion of the bullet and can lead to serious over pressurization, and possibly a "ka-boom", or catastrophic failure of the barrel.

just what I've heard anyway.

surv

For me, when the clothing allows, it's a Sig 239/40 chambered and decocked. Any other time it's normally some form of Kel-Tec (more compact) chambered.