I think these are flying a little slow. Regulator is untouched but I have the Hammer spring maxed out. Same setting will throw a 14.3gr CPHP @ 1099FPS.
Was shooting off of the bipod, no rear support. Scope is 3-9x bugbuster. These slugs seat very tight into the breech (.217). I think I'm going to source some ~20gr slugs to see if I can bring the velocity up without touching the regulator.