Each muzzle loader has certain likes and dislikes...

My Knight Disc likes 300 Barnes over 250 Barnes...My brother's Remington prefers the 250s...
Mine doesn't like 250 or 300 Hornady .451 XTPs...
Hates 295 PowerBelts and Dead Center 240s...
Loves 250 SSTs...Hates 300s...

A few years back (maybe 6-7)...Me and 2 of my buddies all bought new inlines...All Knights...One Wolverine, one American Knight and my Disc...I spent all summer working up loads for all 3, for our annual early season trip down east...Ended up each of them preferred 3 different bullets...Go figure...

Shoot it....only your gun knows for sure....