I had an interesting chat with old friend Sam, a fancier of fine single-action revolvers, who is a fan of the .38-40 Winchester, but has longed for a modern, rimmed .40 cal. revolver cartridge with correct capacity for smokeless powder, for use in a modern, strong revolver, like a Ruger, at about 25,000 psi.
The design intent is to use common .44 Special or .44 Magnum brass as feedstock and either .38-40 or .40 S&W bullets. The case necked and shortened to 1" to have a capacity similar to the 10mm auto, but in RIMMED case, better suited for REVOLVER use. Sam and I both plan to rechamber a New Model Ruger .357 and rebore the barrel.
Another buddy Dave is looking to redo a .401 Herter Powermag
We call this the ".40/.44 Hotton Hammer," description follows:
Base brass to be shortened and necked down is either .44 Special or .44 Magnum.
Case would be necked down to .423 outside diameter, exactly same as the 10mm auto and .40 S&W.
Cases will be trimmed after necking to 1.0" overall length with neck length 0.3"
Necks will be reamed to 0.010" wall thickness to provide safe release clearance for a .401" diameter bullet.
Shoulder angle is 6 degrees, 48 minutes Basic, same as the .38-40 Winchester.
Case body diameter of finished case is .454" at shoulder, same as .38-40 and .457" at base, unchanged from .44 Special brass.
Revolver reamer will be dimensioned to cut cylinder throats 0.401" to enable using either jacketed .40 S&W bullets, or .38-40 lead bullets, to be used with 10mm barrel of .400" groove diameter and 16" twist, same as .40 S&W.
With one inch case length, with 0.3" neck length and 1.55" max. overall cartridge, it is possible to load a bullet up to 0.80" long or about 250 grains, if you wanted to take a Swiss Vetterli bullet and shorten it by cutting the heel off.
Our plan is to use Accurate 40-215B, double-crimp groove for .38-40 and 5-6 grains Unique as starting load for about 900-950 fps from 4-5/8" Ruger.
Attachment 197740