$25 7 62x51 NATO Cartridge 3D model by Plutonius3d. Available on CGTrader with 11122 polys and 5567 vertices. Check it out on CGHub.
OBJ (OBJ, filesize: 176 KB), FBX (Autodesk FBX, filesize: 1.31 MB), UNITYPACKAGE (Unity 3D, filesize: 729 KB), 3DS (3D Studio, filesize: 161 KB), MAX (Autodesk 3ds Max, filesize: 681 KB)