suppressors do not lower velocity a single bit. what a suppressor does is disrupt the flow of hot gasses slowing the expansion of the gass from high pressure to low pressure. its like shaking a soda can and instantly popping the tab vs very slowly easing the tab open. the bullet is long gone by the time that occurs.
the only thing that slows a bullet is friction with air or other objects. since the bullet is not hitting a properly attached suppressor there is nothing but air to slow it down.
the only two designs of suppressors that DO reduce velocity over non suppressed are the ones that use wipes where the bullets actually contact material in the suppressor. the second type are guns that use integrally suppressed barrels. integral suppression bleeds of gas through ports in the barrel reducing velocity.
suppressors that do not use a wipe system and screw onto the threads of a muzzle or attach to a flash suppressor brake or other muzzle device do not lose a single fps of velocity.
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