 To handle the extreme pressures of the .454 Casull without changing the design of the cylinder, Ruger used a different alloy and heat treatment process to increase its strength.The frame material is the same as standard Super Redhawks, but frame and cylinder are colored differently by use of a "target grey" finish produced by tumbling the parts in special polishing media.The .454 Casull model is actually marked as ".454 Casull /.45 Colt", and is capable of shooting the slightly shorter .45 Colt rounds.