For the 45 Colt, I especially prefer the 250-grain RNFP and the 255-grain SWC.
There is also a better selection of .429" bullets for the handloader..44 Magnum brass is more widely available, cheaper (because it is discounted more due to higher sales volume), stronger, and lasts longer. For the 45 Colt this is the Single Action Army revolver. I have been asked specifically about this revolver in the past, as their owners sometimes conclude that if the Model 29 can withstand the 36,000 psi (43,500 cup) of a .44 Magnum cartridge, their revolvers should be able to withstand the same pressure. I also have a shooting buddy who regularly shoots very high pressure loads in his Ruger Blackhawk Bisley Model, and we have discussed the wisdom of so doing on occasion.I get e-mail questions on the subject of high pressure loads for the .45 Colt all the time. Over the nearly 15 decades since its arrival, there have been many attempts to pronounce it dead. Then those hot powder loads might have been right around the yield point of my gun's cylinder. Instead of being overly large, Rugers have been way too tight, with some measuring around 0.449 inch, but now Ruger is cutting all cylinder throats at 0.451 to 0.452 inch. These two bullets in a custom five-shot Blackhawk or Freedom Arms Model 83 five-shooter can be driven to 1,450 fps with W296 or H110.The availability of all of these bullets is dependent on how much time I have to cast my own. Any time I have a 45 Colt that doesn’t shoot the way I think it should, I don’t give up until I try this load of IMR 4227 with Keith’s bullet. With all due respect, does this load have any credentials, or references from users of it, other than "I found it on Quickload"? The key for best shooting is to size cast bullets accordingly and open the throats if necessary.This brings us to powders, and I use a lot of Hodgdon powders. Ruger Ruger Or A Cimarron. I would probably be shooting left handed today, and maybe blind to boot.The point is, be satisfied with the high pressure loads listed in the Hornady, Sierra, and Speer manuals. They are plenty enough for the .45 Colt. 45 Colt (Single Action Army & Replicas) Load Data; 45 Colt (Ruger & T/C Contender & Encore) Load Data; Cartridge Data; Components by Caliber; Nosler Home; Load Data 45 Colt (Ruger & T/C Contender & Encore) Load Data. Perhaps the best known of these companies is Cor-Bon. 45 Colt (Ruger & T/C Contender & Encore) Load Data. 62x39mm Military Ammunition 120, SKS U. Rifle 45 Colt Rifle Load Data Model 92. Further, I'd guess that the maximum pressure of that 300 grain bullet load was pretty close to the maximum pressure of the Hornady load for their 250 grain bullet or the Sierra load for their 240 grain bullet.So I accept that Speer's 25,000 cup is indeed a reasonable maximum pressure for high pressure .45 Colt loads intended for use A little simple arithmetic shows that a 25,000 cup load is slightly more than 57% But what about other modern revolvers chambered for the .45 Colt cartridge? )Speer's top load for both the 260 and 300 grain bullets used Winchester 296 powder. The 45 Colt also predates the 38 Special, the 44 Special, and the 45 ACP, and not only is it more than 80 years older than the 44 Magnum, but it also has more case capacity and in the proper sixguns can outrank the 44 Magnum. I read an article by Mr. Linebaugh in which he claimed that Federal makes the best .45 Colt brass. Keith’s #454424 was an excellent bullet, but it has been improved by Dave Scovill and is offered by RCBS as #45-270SAA. Air temperature and density, bullets, powder lots, primers, cases, crimp pressures, powder measures, powder scales, chambers, barrels, barrel and chamber temperature, and so on are all variables that can affect pressure. For the purposes of this article, by "high pressure" I mean pressures above the industry accepted SAAMI maximum pressure limit. We are blessed to have many excellent cartridges and sixguns available to us, but it would be hard to find any cartridge that is as versatile as the old 45 Colt. NEVER use any high pressure .45 Colt load in a S&W revolver. If I remember correctly, it was an Italian-made Peacemaker replica, which did sour me on replicas, probably unfairly. We were soon shooting 300-grain bullets at 1,200 fps from a 7.5-inch-barreled Ruger revolver. I have W231 but have found no data that reaches 900 fps.
It should be since the .44 Magnum operates at about 2.5 times the maximum SAAMI pressure of the .45 Colt.It is a tribute to the quality of modern .45 Colt brass that it has proven safe (in Blackhawk and Contender guns only) with maximum pressures about 57% greater than the SAAMI limit.
And the hardness of a bullet's jacket and core influences pressure. I also have been having good luck lately with 10.0 grains of HS-6 and 250- to 260-grain bullets, which duplicates the performance of the early black powder loads. This means you have the option to read your magazine on most popular phones and tablets.To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine. That brings us to the next level, which includes 45 Colt revolvers built on the Ruger Super Blackhawk frame and the Ruger Old Model Blackhawk, the arrival of which led to two separate load sections showing up in loading manuals. The 45 Colt brass was up to the task. When Ray Thompson was designing his line of bullets, he did not neglect the 45. For the .45 Colt cartridge that is 14,000 psi as measured by the relatively new piezo-electric transducer method, or 15,900 cup as measured by the older copper crusher method. (NOTE: Sections marked “Ruger Only” are not for the New Model Blackhawk Flat-Tops or the New Vaquero!) Now consider what would have happened if I had been bold (and imprudent) enough to load reloads that were intentionally 50% over pressure? At first I thought the gun had blown up.