We, for the most as civvie CCW'ers tend to romanticize the hand gun as the ultimate tool of the warrior against evil, how some ever, that is because we would get a lot of funny looks if we were to go walking about with an M-4A1 carbine.
I would stick to making the protagonist's primary being as authentic as possible and also his most used weapon.
NRA Life Member
Me: "The .45 GAP was an answer to the question nobody asked."
Trooper pal: "Says the guy who thinks .38 Super and 10mm are viable pistol calibers and gets mad when Wal-Mart doesn't have them."