Originally Posted by
SAWMAN
It is inertia. When the butt of the gun is hit on the ground,the BCG moves to the rear just enough to take it off the bolt catch (hold open). The bolt catch retracts and the BCG slams into battery (closes).
We used to do this with some of our guns. I did it with my XM177E2 or M16 back in the day.
*Pull charging handle to the rear and engauge bolt hold open (bolt catch).
*Close charging handle.
*Close ejection port cover
*Safety on safe (or fire).
You could either tap the butt of the gun on the ground or hit it with to heel of your hand and the BCG would slam forward.
CAUTION: I am not endorsing this practice for the civilian environment or even members of the military. --- SAWMAN