Most modern .45 pistols employ a system of operation where the barrel and slide are locked together to contain the pressure of discharging a cartridge. In these systems it is necessary for the barrel to move within the frame, either in a straight line or with a tilting motion. AAC's A.S.A.P. Clutch™ system used in the Ti-RANT series takes the weight of the silencer off the barrel, allowing it to move and the host pistol to function in a normal semi-automatic fashion. On weapons with non-moving barrels the A.S.A.P. Cluthc™ system is not necessary and may actually damage the host firearm. This fixed barrel spacer replaces the driving spring in the A.S.A.P. Clutch™ system and allows users to safely use their Ti-RANT 45 silencer on host firearms with non-moving barrels.