I am a huge fan of anything .45-caliber, especially single-action revolvers. I have five Ruger Blackhawk revolvers in different barrel lengths, all chambered in .45 Colt, two of which have extra cylinders chambered in .45 ACP. Since .45 ACP ammunition is more plentiful for me, I shoot more of that cartridge than I do of the .45 Colt.
I contacted Ruger’s customer-service department to inquire about obtaining .45 ACP cylinders for my three revolvers that only came with the .45 Colt cylinder, but was told in no uncertain terms they didn’t provide that service.
The expense of having cylinders made for the guns being more than I expected, added to the admonition from Ruger’s customer-service department about aftermarket parts installed on its guns voiding the warranty, spawned another idea. Why couldn’t I use the .45 ACP cylinders that I already had in the guns that originally came without the extra cylinders?
What guidelines and precautions should I follow in seeing if the cylinders that I already have will function in any or all of the revolvers that I have? If it works, it will save me some money and add to the enjoyment that I have in shooting all five of my Ruger .45s.
Jim F. , via e-mail
I, too, am a fan of .45-caliber handguns in both revolvers and semi-automatics.
In fact, I found myself in a similar predicament more than a few years in the past, in my military career, where Brown Box ball ammunition was plentiful for our issued M1911A1 pistols.
I had a .45 Colt Ruger with a 7.5-inch barrel and an extra cylinder in .45 ACP. I also had a .45 Colt Ruger with a 45/8-inch barrel that was more convenient to carry, but without the extra cylinder.
I knew that the tolerances in the Ruger pistols were held to a fairly close standard, so I started to work on seeing how close those tolerances were in an effort to determine if there was a safe compatibility from one gun to the other.
The first thing that I did was install the .45 ACP cylinder in the 7.5-inch-barreled gun in order to take a few measurements and perform a function check on the rotation and timing of the cylinder. This information would give me a baseline to work from when testing the cylinder in the 45/8-inch-barreled gun.
After taking the measurements and checking the timing, I installed the .45 ACP cylinder in the 4 5/8-inch-barreled revolver. Once in the gun, I rotated the cylinder on the base pin to ensure that it rotated freely. Next, I checked the end shake (forward and backward movement of the cylinder in the frame) with a feeler gauge to ensure that it fell within the .002- to .005-inch range normally acceptable for a single-action revolver.
Once the acceptable end-shake range was verified, the cylinder was loaded with freshly sized and primed brass cases to measure headspace. The distance between the chambered cartridge case and the breech face (where the firing pin protrudes through to fire the cartridge) should fall between .006 and .012 inch on each of the six chambers, leaving the cylinder to rotate without restriction.
The barrel/cylinder gap is checked next to ensure there is a space of .004 to .008 inch between each chamber and the forcing cone at the back of the barrel.
Timing is checked with the cylinder unloaded by slowly thumbing back the hammer to ensure the bolt engages the cylinder-stop notch prior to the hammer reaching the full-cock position. This is done with all six chambers to confirm that the cylinder is stabilized in the firing position prior to the completion of the cocking cycle.
The final step requires a range rod to test the alignment of the barrel with each chamber of the cylinder when locked in the firing position by the bolt. The range rod should enter the throat of each chamber of the cylinder without interference to ensure a smooth transition of the bullet to the forcing cone of the barrel when firing takes place.
Fortunately, in my case, the tests and measurements were all within recommended specifications and the .45 ACP cylinder worked perfectly in both revolvers.
I am confident that if you follow these guidelines and find that the measurements and tests work within the specifications listed, you will have no problem with the interchange of cylinders that you desire.
Not knowing your mechanical capabilities, if there is any doubt about your progress or the safety of performing the tasks necessary to make the cylinder exchange, I would recommend consulting a professional gunsmith to validate your work before taking the gun to the range.
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