.454 Casull (using Sierra bullets)
Date: Mar 30 2016
The .454 Casull was developed around 1957 by Dick Casull (and Jack Fullmer) by lengthening the standard .45 Colt case to around 1.385 inches, (special machined cases), and loading it at much greater pressures, even exceeding 65,000 psi. Casull designed and built from a block of 4140 steel a totally new five-shot, single-action revolver, but it was not until 1983 that a similar version, crafted from state-of-the-art double heat-treated 17-4PH stainless steel, would go into production as the Freedom Arms Model 83.
In spite of Freedom Arms (and other small companies) offering commercial ammunition, it remained a proprietary cartridge until the late 1990s, when it was officially adopted as a standard SAAMI cartridge. Maximum average pressure is established at 65,000 psi. Most ammunition companies hold their pressures to between 52,000 to 58,000 psi, however, which is wise considering that not all guns are as strong as the Freedom Arms revolver. (When loaded to 65,000 psi, certain double-action revolvers tend to stick cases and exhibit other signs of excess stress.)
When fired from most revolvers, the .454 Casull will push a 260-grain JSP bullet to 1,800 fps, or a 300-grain bullet to 1,600 fps. All loads in the accompanying data are well below industry maximum average pressures and suitable for all guns.
In spite of its name, the .454 utilizes bullets that measure .4515 inch to .452 inch with the accompanying Sierra bullets measuring .4515 inch in diameter. Bullets with a thin jacket intended for standard pressure .45 Colt loads should not be used with maximum .454 Casull loads, or pressures can increase substantially and jackets have been known to separate before leaving the barrel.
From 1957 through 1985 .454 Casull cases were built by multiple sources and featured a large rifle primer pocket. In 1985/86 the primer pocket was changed to a small rifle, with all subsequent cases being built to this specification, which was a significant improvement in several respects. This data was developed with the Federal 205M (match) primers, but Remington 7 ½, CCI 450 or Winchester Small Rifle Magnum primer may be substituted.
The cartridge thrives on classic magnum handgun powders, such as Hodgdon H-110 / Winchester 296 (identical powders), Alliant 2400 and Accurate No. 9. Ball powder loads should not be reduced or erratic ignition and pressures can result.
To keep bullets in place (in both revolvers and lever-action rifles) and achieve correct powder ignition, a heavy crimp is required.