first of all - i think you have done something very, very important most people tend to not care about - realism. (salvo for the top one i guess) most people go just by "if it looks cool, then i'm cool with it", and while there's no real problem with that, c'mon, some of the guns you see around are impossible to even hold, let alone work mechanically.
you somehow managed to combine the "look cool" with the "look practical" and "be workable". it amazes me how much thought you put into the weapon - you even made the internals as well!
though i'm not a fan of post-apoc-esque designs, you also made the bottom one which is a more "clean" configuration. looks really awesome, especially with those textures.
so, sorry for the long comment, but i just can't compliment enough. truly amazing work!
thanx, unfortunatelly 99% of "mechanical designers" never care about workable realistic things, and 100% of their(and mine) bosses as well. and if you know how the fucking damned industry works, probably you'd notice why the only non-ridiculous configuration I placed in the bottom))) ofcause all those trashy-junky mods made not just because I wanted them so much? lol, but because ignorant people who usually takes top management positions in gamedev, prefers this ridiculous bullshit which they call as "cool design that sells good and cost low")))...