I accidentally doubled a 5.7 grain WW231 / 230 gr FMJ load with one of my 1911's. It blew the top off the left grip, blew the plunger tube out and broke the hammer pin. It jammed the next round way down in the mag, the mag expanded.
Shall we blame the unsupported chamber for this????
It ripped a hole in the brass case right at the bottom base, the unsupported area.
I replaced all the broken stuff, works great.
I switched to power pistol in the hopes that the larger charge weights would make a double charge more obvious in the loading process.