Trustworthy load data is rather limited for the .257 Ack. Imp. The Nosler Reloading Guide 9, though, contains plenty of reliable information.

Two sets of handloading data exist for the .45 Colt, due to the myriad guns chambered for the cartridge during the last 150 years. For this load, I referenced .45 Colt (Revolver) data that, “may ...

Many turkey hunters load their own high-performance shotgun ammunition with Tungsten Super Shot (TSS) and Hevi-Shot, but reloading improves performance for all shotgunners.