The 10x25mm, a revolver wildcat, aka .40/.44 Russian
May 10, 2020 14:24:04 GMT -5
awp101, Bagby, and 3 more like this
Post by coltnewservice45 on May 10, 2020 14:24:04 GMT -5
The 10x25mm Revolver Project was a joint effort of John Taylor, Dave Manson and I. The basic concept was a handy "packing pistol" of caliber, “starting with a 4,” throwing “a half-ounce chunk of lead about 1000 fps,” which can be loaded down for small game. We wanted a .40 cal. cartridge, capable of using either .40 S&W or 10mm jacketed or .38-40 cast bullets. The goal was to obtain .38-40 black powder ballistics using smokeless, in a sturdy revolver, using a smaller, sturdy case, formed from common brass, thus avoiding the excess free airspace and fragile nature of .38-40 brass. A case full of black powder or Trail Boss would be adequate for Cowboy Action, plinking, or small game at about 700 fps with either round ball or bullet, whereas full-charge smokeless loads would exceed the .40 S&W and approach the 10mm Auto performance with standard-weight bullets and drive a 250-grain bullet to 1000 fps from a compact revolver. These parameters were met handily.
The .44 Russian case has just the right case capacity. When necked to .40 it has a capacity of 21 grains of 3Fg, 4.5 grains of Trail Boss or 14 grs. of IMR4227 using the RCBS Little Dandy Rotor #18 to fill the case gently without compressing the powder. From our custom 5-inch Rugers by John Taylor, 5 grains of smokeless Bullseye powder exceeds .40 S&W factory ballistics. We attained 1000 fps with Accurate 40-182H and 950 fps with 40-220H cast bullets. With 7.4 grains of Auto Comp we got 1140 fps with the 180-gr. and 1080 fps with the 220-grain cast bullets. Indeed an adequate “packing pistol.”
John Taylor rebarrelled our .357/9mm Ruger Convertibles using a Green Mountain “gunsmith special” 10mm barrel with 16” twist, rechambering one cylinder for each gun to .40 S&W, and the other to 10x25mm. Starline .44 Russian is necked down and used as-is, no trimming or reaming is necessary, producing a 0.970-0.975” case. The shoulder angle is 6 degrees, 48 minutes Basic, the same as the .38-40 Winchester. Case body diameter is .454" at the shoulder, the same as the .38-40 and .457" at the base, and the same as the .44 Special.
John also has our die reamer and can make dies, or you can contact “DougGuy” of cylinder honing fame and he can cutting down and hone out .38-40 Lee dies if you supply A SET OF Lee .38-40 dies, Doug does the mod, and returns your dies insured in small flat rate box about $150 last time I heard.
The Lee die alteration process DougGuy uses is as follows:
1) FL sizer and seater are both cut off by 0.4" and a new thread relief is turned.
2) Neck of the sizer die is honed inside up to .420" diameter to produce a correct fit for loading .400” jacketed bullets, without expanding, but flaring only.
3) Neck portion of the seater die is honed inside to .429" diameter and the ball seat of the seater die is honed up to .402". The modified Lee seater can be adjusted to provide a substantial roll crimp to prevent inertial dislodgement of bullets in heavy loads.
4) Once you have fire-formed brass, you can neck-size, expand cases, seat and taper-crimp bullets by using a 0.525” spacer with your .40 S&W Auto dies.
Anyone ordering this reamer from Manson should specify .40/.44 Special Short Harris Rev1-6/18.
A dip measure made from a .357 Magnum case measures about 21 grains of Goex 3Fg or 4.5 grains of Trail Boss, filling the case “gently to the shoulder without compression.”
The maximum black powder charge is 24 grains using a drop tube or compression die. The recommended 4.5 grains of Trail Boss is a “full charge” load with the 220-grain bullet, not to be exceeded, because Trail Boss should NOT be compressed!
A charge of 3.5 grains of Bullseye with 40-220H gave 760 fps with a standard deviation of only 7 fps and an extreme spread of 29 fps over a 12-shot string. Substituting the 40-224H ogival wadcutter results were almost identical with 748 fps, an Sd of 7 and a 12-round ES of 23 fps., producing satisfying 2-1/2” groups at 25 yds.
Some interesting historical footnotes put our wildcat into perspective:
“The .44 Richards-Mason conversion for the 1860 Army Colt used 20 grains of black powder with a ½-ounce bullet (218 grains) for 700 fps, dating from 1871."
“The British .44 Webley of 1868 used 19 grains Black Powder and a 200 grain bullet for 700 fps from the Royal Irish Constabulary revolver."
“The 1890s, third-generation .41 long Colt with its 1.00" case and 200 grain, .401" diameter bullet was propelled by 21 grains of Black Powder and drove a 200 grain, blunt-nose bullet about 720 fps. Modern Starline brass is 1.050” to 1.100” long and intended so that hand loaders may load either heel-base or hollow-base bullets. A charge of 4.5 grains of Unique and 200-grain bullet approximates factory loads and must not be exceeded in old guns. Elmer Keith wrote in "Sixguns" (1953) that the "41LC was a better fight-stopper than its paper ballistics would indicate" and it was "better for self-defense than any .38 Special load made"
The 10x25 does all that, with better accuracy, easy case prep and can be full-throttled to do about all that anyone needs from a revolver.
Chronographed loads in 5-inch Ruger:
Accurate 40-182H 5 grains Bullseye 1079 fps, 30 Sd
Accurate 40-182H 7.4 grains AutoComp 1138 fps, 14 Sd
Accurate 40-220H 3.5 grains Bullseye 760 fps, 8 Sd
Accurate 40-220H 5 grains Bullseye 1009 fps, 10 Sd
Accurate 40-252H 3.5 grains Bullseye 711 fps, 12 Sd
Accurate 40-252H 16 grains IMR4227 (Compressed) 1091 fps, 12 Sd
