If Jones had any class, he would have told the man to get a 1911, which to a Script writer would come out "Colt 45".
But he's a Democrat
I hate to admit having seen the movie (it's amazing what you'll do to avoid studying), but he does carry a 1911 in "Man of the House". The trivia section on IMDB for the movie notes that it was his personal Colt, which he brought to the set after refusing a prop gun.
from IMDB:
The pistol used by Tommy Lee Jones is not a prop, it is his own Colt 1911 that he brought to the set after refusing to use the prop gun.