I just acquired a pair of Uberti open tops in 45 colt. Shot 50 rounds through them. 30 grs Goex fffg a mixture of beeswax and Vaseline for lube. No problem, hardly any fouling, easy cleanup. The crane is too short there is a fairly simple fix explained on the internet. I found it by searching "tuning 1871 72 Colt open tops". I don't remember how many rounds I fired in each gun as I was just checking them out. Hope this helps. Al