Back2Fronts is an extensive mod that will overhaul your Call of Duty 2 game to a next level. This mod brings more variety, intensity, realism and battle-like experience. Try new weapons, fight new enemies, fulfil new missions and explore new options. Mod is SP and MP friendly (although primary part is SP).
This video captures the Shotgun and GreaseGun in American SP mission "duhoc". Both weapons are carried by AI Allies. Obtaining them from dead Allies is also the only way how to get those weapons (so far).
Know bugs:
1) The Shotgun does not shoot multiple bullets - just single one like a bolt-action rifle - this cannot be corrected.
2) The friendly AI using a Shotgun operates it like a bolt-action rifle - this cannot be corrected.
It's a shame you can't fix it. WAIT mabye you can and the fact you can't is outdated!
it is almost impossible