Best Fittings BSA Superten Fill Adapter
BSA SuperTen, Super 10, Buddy Bottle Filling Adaptor.
Also fits Theoben Rapid buddy bottle. (Not MFR)
BSA barrel blank
Hammer forged, choked, 500MM Barrel blanks from BSA, 12 grooves, 1 in 19" twist.
Available in .22, .25 and .177 and supplied blacked and ready to machien to fit.