A: Joe, since we don't carry the Gamma, we can't put the 2 pieces together to be able to provide you with a definitive answer. Copied and pasted from the QD Blast Shield description:
"The QD Blast Shield is compatible with Griffin Armament's line of SDQD mounts in 7.62 and 5.56mm, including the Flash Comp, Muzzle Brake, Linear Comp, Compensating Flash Hider, and Tactical Compensator. It is also compatible with A2 compensators that fall within the USGI A2 spec blueprinted dimensions. According to Griffin Armament, the Gen 2 QD blast shield will fit all the same muzzle devices as the Gen 1 QD Blast Shield. Although many companies manufacture A2 style compensators not all of them are dimensioned properly. Not Compatible with BCM, BCE or PWS muzzle devices.
Griffin Armament does not guarantee fitment with an A2 style compensator due to the broad tolerance range of both import and domestic devices from various brands. For guaranteed fitment, we recommend the purchase of a Griffin Armament mount or muzzle device. Silencer interface was designed to fit the USGI A2 government contract compliant muzzle devices. Compatible up to 9mm projectiles. The Griffin Armament QD Blast Shield is a shroud, not a suppressor, and therefore does not require a tax stamp."
Thanks for the inquiry.