Duckzilla
"Laugh it up fuzzball"
I agree with the several comments about .45's being on the heavy side, but I got so used to carrying them (not all the time, admittedly) on a job after 23 years that it was never an issue. Also, the OP (forgive me if I'm repeating a question already asked) states in his requirement that the weapon be ablt to be fitted with a tac light. Just wondering why? Simply because in a shoulder rig the chances of the weapon hanging up increases. Also, in serious response to those who suggest a 44 Mag, it's just not a very friendly choice for rapid fire, with the kick.