Pop Stop by Discreet Ballistics

You can find the Discreet Ballistics PopStop here: https://discreetballistics.com/shop/popstop/

First round pop with silencers / suppressors is a thing.  You have turbulent atmosphere inside the barrel and can of your weapon.  This can lead to a POI (point of impact) shift on that first shot.  Additionally you usually end up with some flash and extra decibels.

Discreet Ballistics, makers of super high quality subsonic ammo, tackled the problem.  What they came up with was the PopStop.  A way to introduce carbon dioxide into the weapon system and displace the atmosphere.  Significantly reducing the effects of first round pop.  A pretty cool approach to the problem.