.454 Casull (Rifle)
Date: May 30 2014
Notes from the Lab: .454 Casull (Rifle)
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 exceeding 65,000 psi. Casull first designed and built, from a block of 4140 steel, a five-shot, single-action revolver, but it was not until 1983 that a similar revolver crafted from 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 ammunition companies) offering commercial ammunition, it remained a proprietary cartridge until the late 1990s, when it was adopted as a standard SAAMI cartridge. Maximum average pressure is established at 65,000 psi, but most ammunition companies hold pressures to between 52,000 to 58,000 psi considering that not all guns are as strong as the Freedom Arms revolver. (When loaded to 65,000 psi, certain double-action revolvers stick cases and have been known to freeze cylinder rotation.)
From most revolvers, the .454 Casull will push a 260-grain JSP bullet to 1,800 fps or a 300-grain to 1,600 fps. In a 20-inch rifle barrel, these same loads can turn up 300 to 500 fps greater velocity (and sometimes more, depending on individual rifle specifications).
It should be noted that both the Hornady .452 inch 240-grain and 300-grain XTP-MAG feature a thick jacket and will withstand the maximum loads herein. On the other hand, the Hornady 250-grain XTP-HP is designed for the .45 Colt and is of much lighter construction. As a result, it should not be used with full-house .454 Casull data as high pressures may result.
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. This data was developed with the Federal 205M (match) primers; however, the Remington 7 ½, CCI 450 or Winchester Small Rifle Magnum primer may be substituted.
The .454 Casull utilizes .452-inch bullets but can also be used with .4515- and .451-inch bullets but only if they are of heavy construction to withstand high pressures.
The .454 thrives on magnum handgun powders such as Hodgdon H-110/Winchester 296 (identical powders), Alliant 2400 and Accurate No. 9. The latter two gave the best accuracy with the 240-grain XTP-MAG, while H-110/W-296 reached 2,000 fps with the 300-grain XTP-MAG and gave the best accuracy.
To keep bullets in place and achieve correct powder ignition, a heavy crimp is required.