Lately I've been planning to write a relatively gritty story set in the modern world, here and now really, the main plotline is that the characters are on the run from a rather unpleasant man, now at one point in the story the characters decide to stop running about and arm themselves for the inevitable confrontation. Now comes the part that I need some help with. What kind of guns could they purchase? They travel a lot in the story, mostly small towns with the occasional stop at major cities. What kind of firearms would they be able to purchase on the 'black market'?