Here goes a long answer to a quick question. Over the years I have shot hundreds to thousands of rounds of smokeless loads in my Model 3 Americans, Russians, and 44 DAs. I still shoot a 44 DA Frontier in 44-40 with smokeless. Early in my shooting of these old revolver, I used BP and quickly found that the residue goes everywhere, including under the stocks, inside the mechanism, in the ejector system, not to mention all over the surface of the gun. BP residue is only soluble in water, so you must clean with soap and water if you want to remove all traces. You cannot easily clean the interior of the gun, so mechanism remains contaminated with sulfur and salts. I researched everything I could find before switching to smokeless and have not looked back.

Loading smokeless in old BP calibers required the use of a chronograph to assure me that I am in the velocity range under original BP loads. I have always loaded smokeless in these old guns to around 600-650 fps and never, repeat never, had a problem with the guns. When reloading, I start with Clays powder, which has been shown to have almost an identical pressure curve as BP from extensive testing on old Damascus double barrel shotguns. Original factory loads for 44 American ran around 700-750 fps, so loading to 600+ fps represents almost 20% reduction, which gives me all the confidence I need to assure myself that I am shooting a low pressure load. I also load 44 Russian, using 200 grain LRN instead of the original 250 grain bullets found in original 44 Russian cartridges.

Is there a direct correlation between velocity and pressure, in my mind the answer is yes, BUT physical testing in short barrel revolvers has never been published. SASS has brought to life many antique revolvers made by Colt, S&W, and some others with no recorded dangers or disasters encountered on the range with smokeless powders that I can find. My feeling is if there were problems, SASS would prohibit the use of vintage guns.

For 44 Russian, I currently use a bullet that is 20% lighter than original and around 2.5 grains of Clays, which is 20% slower than original loads. I design all my 44 cartridge reloads to run around 600-650 fps and it still hits what I aim at, with no ill effects to the gun.

The biggest caveat is that these guns are very old and most have seen whatever indignities could have been bestowed on a firearm, so they can and will break over time. Parts are tough if not impossible to find and most will require a machinist and lots of money to recreate.

Low steel strengths have been the biggest reason stated by many in why you should not shoot smokeless in antique guns. I read that the frame will stretch, the latching system will fail, pressure curve is not the same in smokeless as in BP, pressures will spike much higher in a revolver shooting smokeless, steel will lose strength over time, and many more precautions. I ran a quick check of loading Clays in 44 Russian and see that the lowest charge that Hodgdons shows is 3.2 for a 200 grain bullet yielding 747 fps and 8,000 CUP. Comparisons of CUP to PSI has been done, and it was reported that pressures under 10,000 CUP are similar to their PSI equivalent.

Steel was introduced around 1850 and by 1879, ultimate strengths of mild steel was about 60,000 psi and allowable strength was about 14,000 psi. Compare that to the 1900 allowable strength of 16,000 psi, or only a 10% improvement at the start of the smokeless powder era. Bottom line is I like my chances.

__________________
Gary
SWCA 2515