OK, the Freestuff on Daz3D has some sets of Questor's weapons. The modern arms set has an MP-5K, and the sci-fi set has some stuff, but the majority of the guns in those two sets are pistols. Each set is also a rather big download, but the quality is pretty high. There's a folding-stock Kalashnikov from Onyx, and something called an M4 which looks vaguely like an M14, here on Renderosity. The search engine here should turn up other stuff as well. Don't forget that some weapons used in "Star Wars" were slightly tarted-up real-world guns.