It doesn't so much "reduce" the blast as it directs the blast (and sound) forward...
The CQB Comp, originally designed as part of the Diablo Upper, is designed to provide as much compensation as possible while reducing flash and sending all the blast forward of the shooter and those next to the shooter.
The CQB comp is designed for just that - CQB. This product comes by request of those running through buildings that love the FSC556, but the blast in that narrow space is too much, especially for the guy standing next to them.
The primary function is to send all the blast forward. The secondary function is to suppress flash and the tertiary function is to compensate the rifle. This product in no way compensates the weapon to the level of the FSC556 or our other comps, but it does serve the needs of those that requested its development.
This unit is 2.8" in length, 1.4" in diameter and is threaded 1/2x28.
While the FSC556 is fantastic at improving accuracy (tightening groups)... the CQB-556 does not match that same level... but on short barrel AR's it's other features are a fair trade-off
Mark