Check out M16A2 Rifle Low-poly 3D model on CGTrader for $39. High-quality mesh by luchadordev: 54655 polys, 30037 vertices. PBR, Textured, UV Mapped.
MAX (Autodesk 3ds Max, filesize: 274 MB), OBJ (OBJ, filesize: 274 MB), FBX (Autodesk FBX, filesize: 276 MB), DAE (Collada, filesize: 274 MB), TBSCENE (Marmoset Toolbag, filesize: 274 MB), TEXTURES (Textures, filesize: 366 MB), PNG (PNG, filesize: 274 MB), SPP (Substance Painter, filesize: 1.6 GB)