I'm 5'9" and weigh 275. I use a "Summer Special" style holster or a Crossbreed Super Tuck. Wearing the fat boy shirts that fit me, I could almost hide an Uzi. I carry a commander size 45 1911 all steel gun and don't have any printing problems. You need a GOOD belt whatever size you are to make carry more comfortable.
A 45 may not expand but it will never be smaller than .45!!
NRA Patron Life Member