How I'm looking at it...
The die code of the weapon isn't the damage capacity of the weapon...it is the character's skill at using it that the weapon is attributed to.
As has been noted, there is no cost for Beast to pick up the pistol and even gets the benefit of having a narrative excuse to make ranged attacks.
However, he doesn't get an extra die for the weapon (without creating the asset) because it isn't a "normal" part of his concept, as defined by the datafile.
But then again, if you find something that works better for your game, have at it.