Got the same rifle. I shoot 3-777 pellets (150gr equiv pyro), and 250gr barnes with well over 2000fps. I get sub2MOA performance very very consistently. Also shoot 240gr XTP (green sabot) and 95gr of Pyrodex (works great) around 1550fps. I have tried 3-777 pellets and 240gr XTP Mag (black sabot) but you have to use a MMP Mag Subbase to get good performance.

I have a question. I had a huge gap between my forarm and barrel. So much you could squeeze the front of the barrel and the reciever would come up. I had it bedded and glass'd. Wonder if yours is the same.

I shot a doe last week with the barnes load, and all I can say is wow, devastating damage when shot thru the lungs and heart. More trauma than I ever seen with any other muzzleloader load.

I worked long and hard to find an accurate load with >130gr of powder. And it wasn't easy. So don't expect them to work great for you. Just give it a try.