The SilencerCo AC1756 Piston AC1756 1/2"x28 Stainless Steel is designed to be easily changed for different host firearms or calibers, offering quick adaptability for diverse setups. Crafted from 17-4 stainless steel and heat-treated for maximum durability, these pistons stand up to hard use while maintaining reliable performance in demanding environments. As a key component of the Nielsen device, the piston moves to enable semi-automatic cycling for unlocking pistol barrels, ensuring smooth operation across handgun platforms. For fixed barrel applications, a Fixed Barrel Spacer can be tossed in to accommodate varying configurations, enhancing versatility without sacrificing reliability. SilencerCo pistons feature female threading that attaches securely to SilencerCo threaded barrels, delivering a precise fit and repeatable performance when swapping between hosts. XL pistons are available for firearms where the silencer requires additional length between the threaded barrel and the silencer, supporting longer ????????? and maintaining proper alignment. With a 1/2"x28 thread pattern, these stainless steel pistons are built to endure the rigors of regular use, helping to optimize suppression performance and cycling for a wide range of suppressor setups.