Hello,
I use an R&D Conversion on my ROA, but have only shot cast bullets through it. I shoot medium power "Cowboy Loads" with 165gr, 200gr, and 250gr cast bullets no problem. I would guess my reloads run 800 to 900 fps with 8gr of Unique. With jacketed bullets pressure will run a little higher with lower muzzle velocity using a comparable charge of Unique.