As a general rule,outta my 18" bbl handi,using the 350's - 440's,I am gettin' another 300-350fps over the published vels of the "X" frame revo.
These are not max loads, and all were accomplished with H110. A couple of other powders will give you another 30-50fps.
I have a buddy that has a 27" custom bbl for his Encore Pro Hunter, that loads to the max, and is gettin' some super high vels. --- pruhdlr