I've had a chance to do some load testing with my new rifle. Here's what I've played with so far.
52gr FFFg, .440 ball, .018 patch:
52gr FFFg, .440 ball, .020 patch:
60gr FFFg, .440 ball, .020 patch:
I've also tried 40gr with .018 and .020 patches but didn't keep the targets...