Wooden crate, top of crate, shell and cartridge are in separated objects and can be used together or individually in your 3D scenes. 

All LODs are available in the FBX files (for Unity & Unreal) and can be used in the Game Engine you want. 

All Materials and Textures are ready for PBR workflow for Cycles or Eevee rendering in the native Blender file or in Unity / Unreal Engine / Cry Engine / Lumberyard... 

The Unwrapped UVs are non-overlapping and can be re-work to add more details on the surface as leaks, liquid splashes, grease, personal logotype...