It is kinda a AG-36 Grenade launcher with only a few details altered.
At 230 faces(430 Tri) this is a low poly grenade launcher made for blowing up any thing in your way.
All three textures are 1024*1024 to allow for scaling,probably you would want to mix it with the gun it is attached to.
The textures are left "Clean" to allow details to be added later for matching the gun.
SWEEEETTTT, thanks man. appreciate it!