Haven't seen the movie, but untraceable would be my first thought. Unregistered weapon, no brass, no ammunition lot number, home cast lead & home-made propellant (in any run-down motel room). Any number of reasons are possible, but the down-side would be the noise, fire and smoke signature.
Given the arsenal at his disposal though, one still has to wonder why the character would carry such large revolvers, not easily hidden... when he has such a large number of concealable automatics at his disposal.
Last edited by emishi; April 8, 2012 at 04:05 PM.