Check out AK B-13 Zenit Picatinny Rail Low-poly 3D model on CGTrader for $8. High-quality mesh by epick: 8345 polys, 4112 vertices. PBR, Textured, UV Mapped.
OBJ (OBJ, filesize: 642 KB), PNG (PNG, filesize: 8.79 MB), FBX (Autodesk FBX, filesize: 333 KB)