who cares about an unsupported chamber this is only a factor if you reload.
certainly not me, don't reload for .40 cal, and it's never been too big a hurdle for me to buy an aftermarket barrel if I did.
it sure seems to stump some folks though
and while you didn't address it, the billy club syndrome doesn't leave me quaking in fear either. Always figured an extra mag was lighter and more compact to carry around than a billy club anyway. I guess some folks mileage varies on that.
