I was one of them

There is a perfectly logical explanation for all of this. In fact I personally used some of these weapons while participating in this campaign. Some Marine units were not issued nor are they issued heavy/mounted weapons i.e. M249 Squad Automatic Weapons, M240G, 50 Caliber MG, etc. Some units include my unit 1st Force Recon Co, BSP Platoon, or a unit like Explosive Ordnance Disposal. We had to utilize weapons we captured for our stronger defense. As a personal preference I would take a Russian made SVD-Draganov over any sniper weapon we use, ANY DAY!