Tactical Innovations is your one stop shopping solution for 10/22 THREADED BARRELS. The standard 1:16 twist Ruger factory barrels are not designed for the specialized 60 grain SSS "Heavy Bullet", which requires a 1:9 twist barrel to stabilize the longer heavier bullet. Our 1:9 barrels in this section are specifically made for the 60 grain heavy bullet to provide optimal accuracy, performance and stability.