SDI Striker-Fired Pistols (FTH 212) Practice Test

Frame aftermarket modification means changing parts that are part of the gun’s frame or attach directly to it, altering how the gun is held, aimed, or interfaced with the shooter. Upgrading sights fits this idea well because sights are mounted to the gun in a way that interacts with the frame’s alignment and aiming system. Installing better or different sights changes how you visually align the gun with the target, which is a direct frame-level modification aimed at improving aiming. Other options are more about altering the gun’s structure or its internal cycling rather than frame-mounted aiming hardware. Window cutting changes the frame’s physical mass and balance, but it’s typically done to shed weight rather than to improve aiming. Spring replacement and ejector tuning affect the trigger or reliability of the cycling process rather than the frame’s mounting systems. So, sight upgrades best embody a frame aftermarket modification since they modify the aiming interface that mounts to the frame.