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45 Colt Load Data

It's pretty hard to find any other handgun cartridge that is as versatile as the good old 45 Colt. If you're into reloading, here's some valuable load data to get you started.

45 Colt Load Data

In 1935 we entered the “Magnum Sixgun Era” with the arrival of the 357 Magnum; however, long before that we had the 45 Colt. 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. By the standards of the day when it arrived in 1873, and even to this day, the 45 Colt was and is a powerful cartridge. The original loading was a bullet of approximately 255 grains with a muzzle velocity of somewhere around 850 to 900 fps. This was achieved with 40 grains of black powder. On paper, the 357 Magnum was the first cartridge to exceed the 45 Colt’s muzzle energy, but many knowledgeable sixgunners, Elmer Keith included, believed the 45 Colt actually offered more practical power than the “First Magnum.” Today, it remains one of our most popular sixgun cartridges.

The 45 Colt’s Story

Sam Colt became a millionaire producing percussion revolvers. When he died in 1862, the company was dedicated to producing the same percussion revolvers. Then something dramatic happened in 1869: Smith & Wesson brought forth the 44 American sixgun that used fixed ammunition. The day of the percussion revolver would soon be over, and even Colt could see the future and began converting 1860 cap-and-ball sixguns to fire cartridges.

Everyone who has a Ruger Blackhawk or Freedom Arms single-action revolver realizes the roots of these modern guns go back to the Colt Single Action Army. Elmer Keith’s custom Colt single action was used to develop his heavy 44 Special loads in the late 1920s, and for a long time the 45 Colt cartridge was accused of being weak. However, Dick Casull started with the 45 Colt single action and the “weak” 45 Colt case to come up with his cartridge, which eventually became the 454 Casull. The 45 Colt brass was up to the task. When the new “454 Magnum” revolvers (as they were first called) arrived, however, the brass was lengthened so it could not be used in standard 45 Colt sixguns. The 45 Colt brass could handle the pressures, but standard sixguns could not.

45 Colt Sixguns

Before I discuss handloads for the 45 Colt, we have to acknowledge there exists such a wide range of revolvers accepting the 45 Colt that great care must be used in assembling loads and choosing which guns will safely accept them. S.A.A.M.I. sets maximum standards for cartridges; this standard must be set at a level safely usable in the weakest common denominator. For the 45 Colt this is the Single Action Army revolver. Heavy loads that are safe for use in the Ruger Redhawk would destroy a fine Colt SAA. In ranking the various 45 Colt sixguns now in production from the least strongest to that capable of a handling the heaviest loads, I would set the following order. The Colt Single Action Army, Colt New Frontier, Ruger New Model Flat-Top, Ruger New Vaquero, and Smith & Wesson Model 25/625 are all very close strength-wise. Then comes the Freedom Arms Model 97, the original Ruger Vaquero, Ruger Blackhawk, Ruger Redhawk, and the Ruger Super Redhawk. Custom five-shooters built on the Ruger Blackhawk, the Ruger Redhawk, and the Freedom Arms Model 83 top the list.

Actually, we can divide 45 Colt sixguns into several reloading levels, and I have moderated these somewhat over the past several years, with the first two levels being very close together. I normally stay under 900 fps with a 250-grain bullet in Colt Single Action Army revolvers and its replicas.

Moving up to the second level, loads at around 1,000 fps with the same-weight bullet are used in the Colt New Frontier, Smith & Wesson Model 25/625, Ruger Flat-Top New Model, and the Ruger New Vaquero. 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. (NOTE: Sections marked “Ruger Only” are not for the New Model Blackhawk Flat-Tops or the New Vaquero!) Others are the New Model Blackhawks, the Bisley Model, the Redhawk, and the Super Redhawk. The Freedom Arms Model 97 also is in this group.

The final level includes custom five-shot Rugers and the Freedom Arms Model 83.


There are some excellent jacketed bullets available for use in the 45 Colt, including the Sierra 240-grain JHP, Hornady 250-grain XTP-JHP, and the Speer 260-grain JHP, all of which I prefer for deer-sized game. Quality 300-grain jacketed bullets are also offered by all three of these manufacturers. The vast majority of my 45 Colt handloads over the last 60 years, however, has been put together with cast bullets. They are my choice for everyday use and also for hunting larger, tougher game. The original conical bullet found in black powder 45 Colt loads from the 1870s is very close to the Lyman #454190 and the RCBS #45-255 FN.

Elmer Keith was way ahead of his time in developing everyday working and hunting loads. His 45 Colt bullet was #454424 and was available for decades from Lyman. Lyman now offers it as #452424, and it is a 255-grain bullet—or thereabouts, depending upon the alloy used. One problem inherent with the original #454424 was the fact that when sized to 0.451 to 0.452 inch, the crimping groove almost disappears. Keith’s #454424 was an excellent bullet, but it has been improved by Dave Scovill and is offered by RCBS as #45-270SAA. It is an excellent compromise between the 250- and 300-grain cast bullets. It follows Keith’s original idea of three equally sized driving bands, one forming the base, the middle one serving as the top of the grease groove, and the front driving band helping true up the bullet in the cylinder and is located above a generous crimping groove. With my alloys this bullet runs around 280 to 285 grains while at the same time having a slightly shorter nose than the original Keith design so it fits in all Colt cylinders. When loaded in the Colt Single Action Army at around 850 fps, it is a most powerful everyday working load. This same bullet can be loaded to much higher velocity in Ruger’s large-frame single- and double-action sixguns. RCBS also offers an excellent bullet of standard weight with the #45-255KT that has a better crimping groove than the Keith bullet. When Ray Thompson was designing his line of bullets, he did not neglect the 45. His #452490GC was originally made for the 45 Auto Rim cartridge for use in the Smith & Wesson 1950 Target revolver, but I also use the Thompson design, which weighs around 255 grains, for heavy-duty loads approaching the energy of the 44 Magnum in the Ruger Blackhawk. At 1,400 fps it is an excellent hunting bullet.

With the coming of Ruger’s Blackhawk chambered in 45 Colt in the early 1970s, we finally had a sixgun that could tap the tremendous potential of the 45 Colt cartridge. We were soon shooting 300-grain bullets at 1,200 fps from a 7.5-inch-barreled Ruger revolver. There were no 45 Colt heavyweight bullets available at the time, so we sized down 300-grain 45-70 bullets in several stages, going from around 0.460 inch to 0.452 inch. It didn’t take long for manufacturers to offer heavier bullets, and two of the best came from NEI. Both of these are plainbased Keith-style bullets, and their numbers are #310.451 and #325.454, with the first three digits giving the approximate bullet weight. These can be safely driven to 1,200 fps in the Ruger Blackhawk. 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. When time is a problem, actually when sometimes my own energy is the problem, I look to Oregon Trail Bullets. For the 45 Colt, I especially prefer the 250-grain RNFP and the 255-grain SWC. They often equal or surpass the accuracy from my carefully tailored hand-cast bullets.

Handloading the 45 Colt
Great smokeless powders for Standard level 45 Colt handloads include HP-38, W231, and Trail Boss.

There simply is not much that cannot be accomplished with the 45 Colt. However, there are two problems associated with it: case capacity and cylinder throat diameters. Because case capacity is large, trying to produce lighter loads with slow-burning powders can give very poor results. I have found HS-6, Universal, and W231 powders work very well for standard loads, while IMR 4227 bulks up nicely in 45 Colt brass. The other problem, that of cylinder throat diameters, centers around the fact that they vary considerably. For several years Smith & Wesson cut throats at 0.455 inch or even larger, but now they seem to be running at a more proper 0.451 to 0.452 inch. 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. Colt single actions are right around 0.454 inch. 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. Not only do the Hodgdon folks offer excellent powders, but also they are simply some of the nicest folks in the industry. I didn’t realize how many different powders from Hodgdon I use in loading the 45 Colt until I began putting this article together. The company also distributes IMR and Winchester powders as well as Goex black powder. My powders of choice are Clays, HP-38, HS-6, Universal, Trail Boss, H110, IMR 4227, W296, and W231. For loading black powder 45 Colt loads, I use Goex as well as Pyrodex and Triple Seven. Space constraints keep me from looking at all of these powders in depth, but I can cover a few.

Handloading the 45 Colt
The 45 Colt cartridge was originally loaded with black powder. Hodgdon TripleSeven and Pyrodex black powder substitute propellants can be used in black powder sixguns.

Pyrodex P is the equivalent of Triple-F or FFFg black powder. It is my most used powder both in cap-and-ball and cartridge-firing sixguns when black powder loads are desired. Pyrodex is cleaner burning than black powder and results in less fouling of the barrel. However, it cannot be approached the same as smokeless. It is loaded not by weight, but by volume. That is, if the loading table calls for 40 grains of black powder, then one uses a 40-grain volume powder measure for the same amount by volume of Pyrodex. In actual weight, Pyrodex is lighter than black powder, being about 80 percent of the weight of black powder. So if one used 40 grains by weight of Pyrodex when the chart called for 40 grains of black powder, the result would be an overloaded charge. The weight would more properly be closer to 32 grains. Using a 250-grain cast bullet, 37.5 grains by volume of Pyrodex P results in a very potent 987 fps and a five-shot, 50-foot group of 0.88 inch in my revolver. Dropping down to 30 grains results in an easier-shooting 835 fps and a group of 1.13 inches.

Handloading the 45 Colt
The 45 Colt can be very accurate when the right handload is paired with a good gun.

With the 45 Colt, IMR 4227 is almost magical in being able to provide excellent accuracy when other powders will not. In fact, an axiom with me is, “When all else fails, try IMR 4227 before giving up.” Years ago, after tiring of oversized 45 Colt chambers in Colt Single Action Army revolvers and New Frontiers, I started with a 357 Magnum New Frontier, had the cylinder rechambered properly and tightly to 45 Colt, and then had a new 4.75-inch Colt New Frontier barrel fitted. After all the work and expense, it turned out to be a somewhat mediocre performer. That is, until I tried IMR 4227 with Lyman’s #452424 and a 20.0-grain load, and that combination produced one-hole groups. 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. It has never failed me. It also is a most versatile powder as it can be used for standard loads for the Colt SAA and heavy loads for the Blackhawk.

Universal is an excellent powder for the 45 Colt with 8.0 grains under a 250-grain bullet duplicating the old black powder load. 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.

Two other powders for standard loads include W231 and HP-38. A check of Hodgdon’s loading manuals shows these two powders using the same charge weight produce the same velocities and pressures.

As I have gotten older and my hands have become more tender, I find myself moderating my everyday shooting loads. I have found 5.0 grains of Clays under a 250-grain bullet delivers a very pleasant-shooting load at 725 fps and will group all its shots in 0.63 inch at 20 yards.

For many decades reloaders have been arguing over whether or not H110 and W296 were identical. They do provide identical results of muzzle velocities and pressures using the same charge weights, and I use them interchangeably. They are my choice for the heaviest loads especially with cast bullets weighing 300 grains and heavier.

Handloading the 45 Colt

My brass of choice is Starline’s excellent 45 Colt brass with CCI 300 Large Pistol primers for all powders, except I switch to CCI 350 Magnum Pistol primers with IMR 4227, H110, W296, and all black powder and black powder substitutes. My loading dies are from Lee, Lyman, and RCBS, and all of them give excellent service. However, a tight-chambered 45 Colt cylinder may require tolerances offered by a 454 Casull full-length sizing die. All Freedom Arms cylinders are held to very tight tolerances and whether using 45 Colt or 454 Casull brass, I size with a special 454 die.

Handloading the 45 Colt

A favorite pastime of many dedicated sixgunners is sitting around a campfire arguing the merits of their particular choice of caliber. 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. Over the nearly 15 decades since its arrival, there have been many attempts to pronounce it dead. But the 45 Colt is a survivor. It is a good choice for self-defense, long-range shooting, hunting everything on four legs, and just plain fun shooting. It is impossible to go wrong with the 45 Colt.

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