I could pour some powder in them and get a better idea what they would hold if that would be of interest to anyone.

45 Colt: Best of the Oldtimers

The .45 Colt was the evolutionary product of the transition period from cap & ball handguns to fixed cartridges. The 1860 Colt Army revolver had been converted to cartridges by several methods in order to get around the Rollin White patents held by Smith & Wesson. When that patent expired Colt came out with an interim cartridge gun based on the 1860 Army frame. It was made with a recoil plate, a loading gate, and had an ejector rod on the barrel. They were made in both centerfire and rimfire and were called the Model 1872.

The paper-thin chamber walls in the cylinders would not take much pressure. The cartridge used a "heel" type bullet similar in design to the .22 rimfire bullet. Called a "44 Colt", the actual bullet diameter was .452" - the same diameter as the .45 Colt is today. The .44 Colt cartridge was shorter and smaller than the later .45 Colt, measuring only 1.1" in length. It was loaded with a fairly light charge of black powder and used a pointed bullet.

In 1873 Colt introduced the Single Action Army (also known as the "Model P") along with the .45 Colt cartridge. It was the military caliber for 17 years and like most military calibers that worked well in combat, it became popular with civilians. That it has remained a favorite so long after more "modern" cartridges have been introduced is a testimony to its effectiveness. Now more than 150 years old it is still one of the best. 

The original factory loads were pretty powerful. With an advertised bullet weight of 250 gr. at a velocity of 910 fps, it created over 460 foot pounds of muzzle energy. I once re-created those loadings using original REM-UMC balloon-head cases and 40 gr. of Dupont 3Fg blackpowder. I used the Lyman bullet #454190 which is a faithful reproduction of the original factory bullet except it is not hollow-based like the originals were. In my 7 1/2" Ruger .45 these loads averaged 962 fps and produced a muzzle energy of 532 ft. lbs.! No wimps by any means.

(NOTE: It is possible that the original loading was with 30 gr. of black powder. The cartridges were inside-primed copper cases. Those who invesitgate such things say that the 40 grain loading did not start until the 1880's, introduced by Remington. What has been found of original ammo supports this.)

Original .45 Colt copper case inside-primed

In the 1980s some ammo companies tried to heat up the .45 a bit by going to a light bullet at what used to be normal velocities for this cartridge. Their use of a light bullet defeated the whole purpose of the .45 and my use of them has been less than satisfactory. Most are advertised at 1000 fps or so but in actual use do not exceed or sometimes even equal what you can get with a heavier bullet and a full load of black powder. I shot some dogs and a few coyotes with various loads and was never satisfied with the performance I got. On a coyote some loads would not penetrate completely on a crossways shot. And a coyote is not very thick. 

The so-called "Cowboy" loads today are fun to shoot, and many are supremely accurate. But they are loaded too light to be used seriously. They are "game" loads used for playing games, and should be treated as such. Personally I would not use them for anything serious.

By the way, I do appreciate those who shoot full-power blackpowder loads in the "cowboy" matches. They have a handful. Using real loads is much more realistic than using gallery loads, but as Mr. Keith said, "Every dog has to scratch his own fleas" .. so those who play games are free to do whatever is allowed by the rules of the game.

Introduced so many years ago, the .45 Colt still lives. It outlasted those who tried to replace it. The light Smith & Wesson Schofield load has been re-introduced as a "game" cartridge due to its low noise and light recoil. Until then it had been as dead as the man who designed it.  Poor Major Schofield who designed the pistol used one to kill himself down at old Ft Bowie in the Arizona Territory. The Colt Single Action and the .45 Colt ammo outlasted them all.