.45 Colt (Rifle)

By Chuck Hawks

.45 Colt
Illustration courtesy of Hornady Mfg. Co.

The fine old .45 Colt revolver cartridge was never intended, nor was it historically ever used, in rifles. The recent advent of "Cowboy Action Shooting" has changed all that. Both Marlin and Winchester now offer versions of their Model 1894 rifles in .45 Long Colt.

This is kind of amusing when you think about it. The guys who insist on correct period dress and pre-1900 antique or replica arms also are responsible for .32 H&R Magnum, .38 Special and .45 Colt rifles for use in their competitions. None of these ever existed in the American West. Go figure!

Physically, the .45 Colt is a typical, straight wall, rimmed revolver cartridge. Its rim diameter is .512", its base diameter is .480", and its neck diameter is .476". The case length is 1.29" and the overall cartridge length is 1.6". The .45 Colt uses .454" diameter bullets and standard large pistol primers. The SAAMI maximum average pressure is pegged at 14,000 psi.

.45 Colt cartridges are produced for use in handguns by all of the major U.S. ammunition manufacturers. Most produce special "Cowboy" loads with lead bullets. (Lead bullets are required by the SASS.) These same loads are also fed to .45 Colt cowboy rifles, since ammunition commonality was the whole point of .45 Colt rifles in the first place. Unfortunately, none of the ammo makers' 2004 catalogs list the ballistics of their .45 Colt Cowboy loads from rifle barrels.

From a 5" barrel the typical velocity of a .45 Colt Cowboy load using a 250 grain lead bullet is as follows (taken from the 2004 Winchester Ammunition catalog): muzzle velocity (MV) 750 fps, 692 fps at 100 yards. The energy figures look like this: muzzle energy (ME) 312 ft. lbs., 266 ft. lbs. at 100 yards. The midrange trajectory (MRT) of this load over 100 yards is 8.4", which is over twice the MRT of the puny standard velocity .22 Long Rifle cartridge and probably helps to explain why the frontiersmen were not interested in the .45 Colt as a rifle cartridge.

Modern standard .45 Colt revolver loads offer somewhat better performance than the special cowboy loads. The Winchester Super-X .45 Colt load offers a 225 grain Silvertip JHP bullet at a MV of 920 fps and ME of 423 ft. lbs. The figures at 100 yards are 839 fps and 352 ft. lbs.; the 100 yard mid-range trajectory is 5.6".

Winchester considers their .45 Colt Super-X load a personal protection load, not a hunting load. They do not offer a hunting load in .45 Colt caliber, although they do offer hunting loads for a number of magnum handgun cartridges, including both the .45 Win. Mag. and .454 Casull. Nor does Federal, Hornady, or Remington offer .45 Colt hunting ammunition.

You can expect higher velocity from these pistol loads when fired in a 16"-20" rifle barrel, perhaps an increase of as much as 200 fps, but you still don't have much of a rifle cartridge. The powder in pistol cartridges is, after all, intended to burn efficiently in short barrels.

For comparison, Winchester ballistics for their 180 grain Partition Gold .357 Magnum load fired from a 20" rifle barrel call for a MV of 1550 fps and ME of 960 ft. lbs. For their 250 grain Partition Gold .44 Magnum load fired from a 20" rifle barrel the figures are MV 1810 fps and ME 1818 ft. lbs. These numbers are clearly beyond the capability of standard .45 Colt revolver cartridges fired in rifles.

The current Speer and Hornady reloading manuals list .45 Colt loads for use in rifles. These are suggested as suitable for the sport of cowboy action shooting, and use lead bullets weighing from 225-255 grain at maximum MV's up to or near 1100 fps. Both manuals note that a heavy roll crimp is necessary for use in rifles with a tubular magazine. The Speer manual notes that overall cartridge length is critical for reliable feeding in lever action rifles, and must be kept at or slightly below the specified 1.6". These loads are held to the industry specified maximum of 14,000 psi.

The Lyman 47th Reloading Handbook lists considerably hotter .45 Colt loads in their rifle section, pressure unspecified. It is no secret that the modern Marlin and Winchester 1894 rifles are much stronger than traditional .45 Colt revolvers or the old lever action rifles intended for use with black powder cartridges. Presumably the loads in the Lyman Handbook are intended to take advantage of this extra strength, as they were developed in a modern Winchester Model 94AE rifle.

The Lyman Handbook shows a MV of 1054 fps for a Hornady 250 grain JHP bullet in front of 15.2 grains of #2400 powder. The maximum charge of #2400 with this bullet is listed as 17.5 grains for a MV of 1236 fps.

According to Hornady ballistics tables, their 250 grain HP-XTP bullet (SD .175) at a MV of 1250 fps generates ME of 867 ft. lbs. The 100 yard figures are 1023 fps and 581 ft. lbs. The maximum point blank range (MPBR) +/- 3" for the 250 grain Hornady bullet (BC .146) at a MV of 1250 fps is 120 yards; the actual zero distance would be 102 yards.

This makes a .45 Colt rifle roughly comparable to a .357 Magnum rifle shooting the Winchester 180 grain Partition Gold (SD .202) factory load. And, as Winchester does for their .357 Magnum factory load, Hornady rates their .45 caliber (.454"), 250 grain HP-XTP bullet suitable for short range use on deer/medium game.

The most effective .45 Colt rifle hunting loads I could find in any of my reloading manuals were listed in the Sierra Reloading Data, Edition V manual. The editors caution that these loads are for use only in modern Marlin and Winchester rifles.

The Sierra data shows that their 240 grain JHC bullet can be driven to a MV of 1400 fps by 19.5 grains of AA-No. 9 powder, or a MV of 1550 fps by a maximum charge of 21.6 grains of AA-No. 9. Muzzle energy for the latter load should be 1280 ft. lbs., and the remaining energy at 100 yards should be around 785 ft. lbs.

Since Sierra does not publish ballistic coefficients for their bullets, it is impossible to accurately calculate the trajectory of these loads. However, it is reasonable to assume that with a 100 yard zero the MPBR of these loads would be similar to or slightly better than that quoted above for the 250 grain Hornady bullet. In any case, the remaining energy of Sierra's maximum load falls below the generally accepted minimum level of 800 ft. lbs. for deer hunting somewhere between 75 and 100 yards. Even stretching it, the .45 Colt is no more than a 100 yard deer cartridge.

The free recoil energy of a 6.5 pound .45 Colt rifle shooting a 240 grain bullet at a MV of 1550 fps is 10.2 ft. lbs. and the recoil velocity is 10.1 fps. These figures are close to twice that of a .357 Magnum rifle of the same weight shooting a 180 grain bullet at 1550 fps, and roughly comparable to a typical 7.5 pound .30-30 rifle shooting a 150 grain bullet at a MV of 2400 fps.

Why anyone would buy a .45 Colt rifle for hunting deer is beyond me. According to the Sierra Edition V reloading manual, the hunter who yearns to hunt medium game with a rifle chambered for a pistol cartridge can drive bullets of the same weight (and superior SD) about 200 fps faster using the same model of Marlin or Winchester rifle chambered for the .44 Magnum cartridge.

And, of course, Marlin and Winchester lever action rifles are also available in .30-30 caliber, which is a far superior hunting cartridge. The .30-30 can deliver as much energy to the target at 200 yards as a .45 Colt rifle using hot handloads does at 50 yards, and typical .30-30 loads have a MPBR of around 225 yards!

Never the less, the reloader who happens to have a suitably accurate Marlin or Winchester .45 Colt rifle can whip up effective short range deer loads. This considerably extends the usefulness of some of those cowboy rifles.

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Copyright 2004, 2012 by Chuck Hawks. All rights reserved.