Try loose powder. Most will agree with this. Pellits are just a convenience for the most part.
Every gun likes something different, and some guns don't like some loads at all. I try to shoot a couple different loads, and then tinker with what shoots OK. +/- a few grains here and there.
Can't comment on the gun as I only shoot a flintlock, but it applies to what ever you shoot. I have a few guns that just hate certain loads, but will shoot just about anything else.
I just wish I could find some people that like to hunt nearby to give a reason to get a muzzy stamp. I hate going alone.
Venison - The other fast food