My barrel lengths run from 30" to 34". I am running 535 gr cast bullets through the 45/70 and 650gr bullets through the 50/90. I tried a Duplex loading in one off the 45s and it pushed the 535gr to a little over 1400 fps. I haven't chronographed the 50. I am going to try a duplex load in it. they burn a lot cleaner and push the velocity up about 100 fps. I haven't shoot any of the sharps much even though I have had some of them for over 15 years.