https://youtu.be/7wwBKCtKtm8 The Human Engineering Lab's HEL-E4A was the most commonly used suppressor used in the Vietnam War. It was the result of a series of suppressor designs from the Aberdeen Proving Grounds HEL which were developed to balance suppression and back pressure, so that they could operate reliably on a standard M16 rifle. A total
I just think reflex style suppressors that put the expansion chamber around the barrel are neat.