So, this is what I came up with. It's... pretty big.

The thing in the middle, the err.. "bump" - or scope - is actually a Halo-Assault-Rifle-esque ammo counter. I mean, the magazine is too small to be an HMG, and the weapon itself is too big to be an LMG. I might be able to pull it off as a grenade launcher or something, but to me it looks like some kind of heavy, armour piercing... Onos-rifle.
Any ideas/suggestions/criticism/death-threats?
And as with all my drawings, feel free to edit it at will. At some point I'll start working a bit more on it, adding some minor details and stuff.
Anyways, thanks for your time,
-Sid





