Dave
For a better bullet-dollar value - plus the ability to re-order those 375 gr SSBs, try some of these Buffalo "Keith Nose Replicas" available at this website in 225, 252 & 302 grain. Scroll all the way down the page -- right near the bottom.
Made of soft, pure lead with a truncated cone. A large hollow point combined with a boat-tail base assures flatter trajectory and maximum expansion at all muzzleloading distances.
Buffalo Sabot/Bullets
OR
You can order any Buffalo conical, roundball or sabot/bullet PLUS get those SSBs you have in other grain sizes like 285 or 325 grain by calling them by phone.
Buffalo Bullet Co
1-800-423-8069