Jaz,

You could get 1,800 FPS with the non-canister powder we are using, but, not with the 425 grain slug. My recollection is the pressure of the Fauneta substitute ammunition some of us are fooling around with is above or at the limits of SAMMI specifications for the 20 Ga.

The RBL Professional apparently used Verney Carron barrel blanks, just like Hastings, so the twist is 1:24". I'll be fooling with sabots first. I think they were regulated for the remington copper solid (sabot) slugs - 290 grain @ 1500 FPS. My favorite 20 gauge sabot loads are the Federal tipped expanders (Barnes, 290 grain @ 1,900 FPS), but these guns have 2 3/4" chambers. I have sabots as components, so I may use the muzzle loader component bullets (Barnes tipped expanders) and roll my own in the shorter case.

So, anyone have a 20 Ga Hastings barrel? I'd like to know it's prefered diet.