Give your FX Airgun a serious accuracy upgrade! This kit swaps out the standard interchangeable liner system for a press-fit STX Superior liner housed inside a 14mm OD solid steel tube — no more play, no more flex.

The thick-walled steel housing eliminates the need for o-rings and creates a tight, precision fit between liner and housing. That added rigidity means a more consistent point of impact shot after shot, especially when you're pushing slugs at higher power levels where barrel flex really shows up on target.

Compatible with most modern FX platforms (Impact, Dynamic, Panthera, King, DRS and more). Each kit includes the solid steel housing, Superior liner, barrel inlets, and liner locknut — pick your caliber and barrel length to match your rifle.

Best for: shooters chasing tighter groups with slugs, or anyone looking to stiffen up their FX barrel for more predictable long-range performance.