The Lock-N-Load Speed Sabot projectile is the closest thing to a cartridge that you can get for your muzzleloader. They allow you to preload pellets onto Hornady exclusive SST-ML bullet (now with Flex Tip technology) prociding a convenient way to accomplish fast loading and reloading of the most accurate and deadly blackpowder projectiles ever developed. The SST-ML flies flatter, hits harder and expands better than other bullets on the market. Mfg: Hornady