SIG SG 540 (Subdivision ready 3D model) is available on CGTrader for $39. Original author: Polygate2. Specs: 61819 polys, 62928 verts.
OBJ (OBJ, filesize: 1.38 MB), 3DS (3D Studio, filesize: 311 KB), C4D (Cinema 4D, filesize: 1.21 MB), MAX (Autodesk 3ds Max, filesize: 8.89 MB), BLEND (Blender, filesize: 1.52 MB), MA (Autodesk Maya, filesize: 2.15 MB), MEL (Maya Mel Script, filesize: 2.15 MB), FBX (Autodesk FBX, filesize: 2.8 MB)