My comment was on cheap as opposed to expensive handguns being used.
BTW, how does 50% + 3% + 2% add up to 100%? Is there some third category of firearm of which I’m not aware?
The 50%, 3% and 2% are percentages of all murders. Guns make up about 2/3 or all murders, but there is a catchall of unknown guns that makes of about 13% of the total.
I suspect a fair number are homemade, and there is no category for that. They would likely be in the “unknown” 13%.
Here is an analysis of a variety of guns taken from criminals at one police department:
http://www.buckeyefirearms.org/node/8579