It is common practice to leave behind altered ammo as booby traps, when bugging out of a position.
Why not guns?
We've been dealing with Junior Varsity tier shilling for so long, I'm starting to think they actually did send their very best.
The answer lies with an analysis of the accomplishments of the enemy.
Can you name a single thing they have tried, that hasn't been, or isn't in the process of being, blown out of the water?