Yes, I started at 70 grains and it shot ok, but my ball was too small at .678. Later, after I got a .690 ball it shot better and better still at 90 grains. I decided to stop there based on the barrel inscription. But with this new information I will keep going. With that twist rate I suspect it will continue to improve as I move up in charge. I don't want to strain her but 75 grains is a pop gun load in a bore of this size.