Developed by Dick Casull, Duane Marsh, and Jack Fulmer, with work beginning in 1959 and proceeding into the 1960s, the 454 Casull was standardized about 1983. This development followed the same path as the 357 and 44 Magnums. The difference is, the 454 started out with a longer case and Casull insisted on the revolvers built for the 454 being made from the highest-quality steel and heat-treated to allow safe use of extremely high-pressure loads. This can accurately be viewed as the original no-compromise high-performance revolver chambering. With a case 0.1-inch longer than the various revolver Magnums (357, 41, and 44) and the 45 Colt, and with a working pressure standardized at 65,000 psi, the 454 can generate hunting-rifle-energy when loaded with bullets from about 240 grains to about 350 grains. My personal favorite hunting load for the 454 Casull launches a 530-grain full-wad-cutter at about 1000 fps and delivers as much energy at 100 yards as any feasible 300-grain load can. My WC load has far less recoil, exemplary hunting-bullet terminal results, and does not generate muzzle blast that will most assuredly seriously and permanently damage ones’ hearing with one shot without hearing protection. The downside: this load requires special techniques to glue the bullet in the case to avoid bullet pull. With all loads, bullet pull is a significant problem in the 454. The handloader must use due caution to assure adequate neck tension. Equally, avoid use of H110/W296 for top-end loads because the highly compressed propellant charge of such loads generates so much plastic force on the bullet base that it can be impossible to keep the bullet in place against recoil in a revolver, particularly when the shooter does not have a solid two-handed grip on the gun. This is exactly the scenario that has gotten at least one hunter badly mauled. His ammunition proved perfectly fine when tested with dry hands and a two-handed grip on the gun. Then, when he was attacked by a grizzly, he had only one, wet hand with which to grasp and fire the gun. When he did so, the gun rotated freely in his wet hand and recoil pulled the bullet from the next round out of the case far enough to prevent cylinder rotation, so he had no second shot! Firing that first shot converted his powerful repeating revolver into a functionally empty single-shot that was an almost useless club. For this reason, Accurate #9 and 2400 are far better propellant choices. Maximizing neck tension is critical in any full-power 454 load. Remove all lubricant from the neck interior and use at least 0.006-inch interference fit between bullet and case neck. As with any revolver round, best practice is to apply a roll-crimp after seating the bullet. A roll-crimp eases loading of rounds into the cylinder and can help limit bullet pull under recoil if only modestly. I cannot too-strongly recommend getting a second seating-and-crimping die so you can have one adjusted to only seat the bullet and the second adjusted to only crimp the case mouth. Generally, attempting to do both operations in one step is a recipe for damaged and destroyed cases.