If I was shooting your rifle, I would get a pack of Thompson Center 240 grain Mag Express w/sabots and a pack of Hornady XTP's 300 grain with sabots. Shoot about 80 grains of your Pyrodex RS or P and get sighted in and set. The 300 grain shoot real good out of my Wolverine. So do Shockwaves actually.

All too often I used to monkey around and then at the last minute had a rifle with a load I could not trust. Even if you ordered the Sierra they might take a couple days to get to you. Although MidSouth is real good about fast shipping. Graf's can take a while. The XTP's you can buy local normally and the price is good and you do not pay shipping, and they are in your hands for testing.