Peter - I've heard that Hodgdon is selling a new phony BP. I can't use any of it in my flinters, of course, but I'd never use pyrodex again - the fouling is corrosive after it soaks up some moisture and is difficult to get out of a bore. I don't know what you're using, but all my real black powder is GOEX 3F, GOEX 2F and GOEX 1F. Are you sure the GOEX 2F you are using isn't real BP - I mean- that's what the real stuff says on the red can & it's black, a bit dusty with small irregular granulations of fairly consistant size.
Hodgdon's new phoney is White something, then there's T7 and Pyrodex, Black Mag 3 and Clear Shot. I am not aware of any that are called GOEX 2F.
A 3 dram load should produce around 1,150fps to 1,200fps. A ww .735" ball should weigh just over 1 1/4oz.

Daryl