wouldn't at 9mm sub machine gun have more stopping power ?
Stopping power? Against zombies? Why? Sure, the H&K 4.3mm round has drastic drop off in penetration past a certain point, but it's wounding capability is greatly enhanced by the fact that the round yaws upon penetration of soft tissue. But that's irrelevant. The character of Tallahassee is a comedic character who is not interested in wounding ballistics. Besides ... ANY full auto gun (when body shots don't affect your target, like the Undead) is a complete waste of ammunition.
Mossberg 500 Shotgun
Winchester 1892 "Mare's Leg"
Tallahassee (Woody Harrelson) carries an 6 shot Winchester 1892 "Mare's Leg" with a standard lever, not the enlarged loop of other versions of the gun - .44-40.
Stainless Steel M1911A1
Tallahassee (Woody Harrelson) fires akimbo with two pistols in the shootout at the carnival. The one in his right hand is a Stainless M1911A1 Variant - 45 acp.
Satin Nickel SIG-Sauer P228
Tallahassee (Woody Harrelson) left hand gun during the fight is a Satin Nickel SIG-Sauer P228 - 9mm.