Some Good .44-40 Information
Posted 10 January 2007 - 09:35 PM
Some of the terminology here is confusing to me, so let me try to just set forth my understanding of the issues with 44-40 revolvers. FWIW, I've been shooting single action 44-40's for years, and have spent years working them out, so I think I have a pretty good handle on things.
Originally, the standard bore major diameter (in the grooves) for 44-40 was .426, give or take. 19th and early 20th century 44-40 firearms are typically found with bore major diameters of .425 to .427. As a result, commercial 44-40 ammo is generally loaded with bullets sized to .426 or .427.
Around the same time that Winchester introduced the 44-40 (originally known as the .44 Winchester Central Fire, or .44WCF), Smith & Wesson developed a cartridge for the Russian government. It was the .44 S&W American cartridge, but with an inside-lubed bullet instead of the heeled bullet used in the .44 American. It became known as the .44 Russian. The .44 Russian used a bore major diameter of .429, and nominal lead bullet size was .430 to .431.
The .44 Russian was later lengthened to create the .44 S&W Special. The .44 Special was lengthened yet again in the 1950s to create the .44 Remington Magnum. The .44 Russian, Special and Magnum all use .429 bores and, therefore, .430 lead bullets.
At some point in time, various manufacturers responded to a perceived demand for "dual cylinder" revolvers chambered in both .44 Special or Magnum, and .44-40. Since the bore sizes were slightly different, however, they had to use the larger Russian/Special/Magnum bore, rather than the smaller 44-40 bore. Colt offered dual cylinder 44-40/44 Specials for years, for instance, and the dual cylinder models all had .429 barrels, while dedicated 44-40 revolvers wore .426 barrels.
It didn't hurt anything to shoot undersize 44-40 bullets down the larger barrels, though they might not have had the best accuracy and leading was theoretically more of a concern. If you had tried to force jacketed .430 magnum bullets down a .426 bore, however, bad things might have happened. Thus, the larger bores had to be used on the dual cylinder guns.
Later, some manufacturers apparently standardized on .429 barrels for all of their ".44" firearms, regardless of whether they were 44-40 or one of the Russian/Special/Magnum guns. Uberti, for example, appears to have been using .429 barrels exclusively on 44-40 firearms for many years. I've slugged any number of Uberti-made revolvers and rifles chambered in 44-40, and all had bore major diameters of .4295 +/- .0005. The reason for the standardization is almost certainly reduction in inventory and manufacturing cost.
Today, you really should slug any 44-40 firearm to verify the bore dimensions if you want to ensure best accuracy. It could range from .425 to .430, depending on who made it and when, and how tight their tolerances were. Most Colts and USFA's (other than dual cylinder models) will run .426, and most Ubertis and Rugers will go .429, but I've seen exceptions here and there.
The other important dimensions are the throats, and the chamber necks. For best accuracy in a revolver, throats should be .001 to .002 above bore major diameter. Thus, for a .429 bore, throats should be .430 to .431. Anything larger and the bullet may cock prior to entering the forcing cone. Anything smaller and the bullet will be swaged down to smaller than bore diameter before entering the cone. Both are bad for accuracy and can result in excessive leading. Ruger for some time had badly undersized throats on a lot of its .45 Colt revolvers, for instance. I've generally found Uberti and USFA 44-40 throats to be correct, however. All of my 44-40 Uberti revolvers with .429 barrels have correctly sized .4305 +/- .0005 throats.
Finally, you have the chamber necks. The chamber neck size determines the maximum cartridge diameter at the neck. If it is too small, you won't be able to get a cartridge with a large bullet to seat fully in the chamber. This is where I've come across the most problems. SAAMI spec for 44-40 chambers is .4435 at the case mouth. That spec is based on the original cartridge dimensions, however, which in turn used a .426 - .427 bullet for the standard .426 bore. The problem is that modern brass tends to run about .007 thick, and loading it with a .429 or .430 bullet can result in a cartridge that is too big at the neck to fit in a SAAMI spec chamber. For example, say you have a revolver with a .429 bore, .430 throats and SAAMI spec .4435 chamber neck. If you load a .430 bullet into brass that is .007 thick, you get a cartridge that measures .444 at the mouth, and that .444 cartridge is not going to fully seat in a chamber that is only .4435 at the neck. When you add in tolerance stacking issues, you may find that you can't reliably get any bullet larger than .427 or .428 to work, because anything larger results in cartridges that won't chamber.
At that point, you have a choice. You either live with shooting bullets that are smaller than your bore size (bad for accuracy and promotes leading), or you have the chambers opened up slightly at the necks to accommodate the larger bullets. The latter approach is the one I use. I had a customer chamber reamer made by Manson Precision that opens just the neck area of 44-40 revolver chambers by an additional .002, giving me enough space to reliably seat cartridges loaded with .430 lead bullets. My 44-40 revolvers now work great, with excellent accuracy and no leading at standard velocities.
Posted 11 January 2007 - 12:53 AM
Posted 11 January 2007 - 09:14 PM
Those .44-40's are REAL touchy on adjustments. I smashed more than one case!
Posted 11 January 2007 - 10:13 PM
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