robhof
I've also used the 4f in my ROA, the 1st time was when I brought it and my flint rifle to the range and ran out of the pyrodex that I was using as my main propellent in the ROA, had a full primer horn of 4f for the flint tray. I put in 35 the 1st time and it shot just fine so I added the extra 5 and what a bang, I ended up emptying my primer horn too. The ROA manual says any granulation of powder can be used, but best results can be had with 3f, I got excellent accuracy with 40gr of 4f a wonder wad and round ball.