So I am new to glocks and reloading for them. I have been doing a lot of reading and most seem to recommend an aftermarket barrel for brass life do to the generous size of the glock chamber. My question is why not leave the bulge in the brass at the head. Once it has expanded to fit the chamber it shouldn't expand anymore. I can see brass not lasting long if you are work hardening it every time you resize and shoot it again. Does this just not work for some reason, trouble fitting rounds in the mag maybe?