I present, with minimal changes, the M438A.
A little info on the name. M438A, obviously based on the original M4 model but fires a high-energy density, triple-base, Nitroglycerin, .38 round. Also, it's the
Assault version of the model.
It has a reflex sight, rotatable fore-grip and an extended chamber for recoil and noise reduction.
Currently working on the M438LR, a long range rifle with a powerful, video scope. It's going to use a electron-plate with a reflection-proof plastic film to prevent flare's.