Size matters

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In my early sixgunnin' years I religiously measured the groove diameter of sixgun barrels by tapping a pure lead slug down the barrel with a wooden dowel and then trying to measure the diameter of the bullet. Enlightenment came when I finally realized the barrel diameter was not the most critical measurement; it was the chamber throats of the cylinder which matters the most as cast bullets would be passing through these tunnels long before they arrived at the barrel rifling; the less distortion when they get there the better.

When this became apparent to me I stopped measuring barrels, and with .44 and .45 sixguns, gathered sizing dies from .428" to .432" for the .44 and .451" to .454" and simply used the largest bullet which could be pushed through the cylinder throats. I cannot tell you the barrel dimensions of any sixgun I have, however I can tell you the exact size of the chamber throats.

Several years ago I purchased a set of steel plug gauges measuring from .250" to .500" in increments of .001" and they have turned out to be one of the most important tools on my reloading bench.

VARIOUS .45s

If you start to measure throats it's amazing the differences found from manufacturer to manufacturer and also from time-frame to time-frame. The .45 Colt can be one of the biggest headaches as far as accuracy if you just use ".45" bullets without paying attention to their actual size.

In measuring .45 Colt cylinders of recently manufactured revolvers in my working collection I found the smallest to be a Ruger Vaquero at .449" and the largest an S&W 25-5 at .457"; that is .008" difference and it is obvious you can't just load a box of .45 Colts which will work in both sixguns. The Ruger has now been opened up to .452" but it is impossible to shrink the .457" dimensions down, however bullets sized to .454" give acceptable results.

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In measuring two old .45 Colt Single Actions from 1881 and 1917 the chamber throats were round to be .448" and .455" respectively, so the problem is certainly not a new one. For most .45 Colt revolvers today either .452" or .454" bullets will give good results.

.44 FUMBLING

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When it comes to .44 revolvers there are also great differences in chamber throats. Smith & Wesson has been making .44 caliber revolvers since 1869. That first .44, the S&W American, used a heel-type bullet, however the Russians convinced S&W to place the bullet inside the brass case and the .44 Russian was born. S&W also produced 19th-century revolvers chambered in .44-40, added the .44 Special in 1907 and the .44 Magnum in 1956. With this long history you might expect them to have come up with a uniform measurement. Not hardly.

I have found .44 Russians at .431 ", .432" and .433"; and Smith .44 Specials in every increment from a Model 696 at .428" to a Model 624 at .432"--and these two sixguns were made within a few years of each other. I have found Colt .44 Specials from .429" to .433" and Colt .44-40s all the way from .424" to .429".

Normally, but certainly not always, .44 Special 2nd Generation Colts will be fighter than 3rd Generation Colts and this difference is usually about .004" from .429" to .433", however with .45 Colts the measurements can be all over the map from .452" to .456" in either Generation. When it comes to the .44 Magnum I have found some as small as .428" while the largest is at .433". Usually I have .45 Colt loads on hand with both .452" and .454" bullets and with the Special and Magnum .44s I stay stocked up with handloads using both .429" and .431" Keith bullets.

The only way to get the best accuracy out of a sixgun is to use bullet diameters dictated by the size of the chamber throats. If you are having accuracy problems with a .44 or .45 of any stripe, measure the chamber throats carefully, use some properly sized Keith bullets, and enjoy life once again. No stress; no strain--no frustration.

COPYRIGHT 2008 Publishers' Development Corporation
COPYRIGHT 2008 Gale, Cengage Learning