I recently purchased a nice old Cadet, and during the course of studying it, discovered that the bore slugged .321, which falls within the typical range for these rifles. The brass for this cartridge is frequently made by trimming 32-20 cases back to 1.120" and thinning the rim about .010". Many Cadets will chamber a shortened 32-20 case with no thinning of the rim. I found this to be the case with my example.
The .310 Cadet cartridge was designed to use a heeled bullet of .323" diameter with a .310" heel.
Just out of curiosity, I decided to insert a .322" diameter "O" buckshot in the mouth of one of the trimmed cases to see if it would chamber,...and was surprised to find that it did!
The outside diameter of the mouth of the cartridge measures .334 after it's expanded by the seating of the .322" ball, yet the cartridge readily chambers.
This convinced me that I could use heel-less, full diameter bullets in my cartridges and make the loading process as simple as for any conventional modern cartridge.
I started digging around for any bullets I might have on hand which matched the groove diameter of the Martini and came up with some old Yugoslavian military surplus cartridges in 8mm Mauser. After pulling one of the bullets, I found that it measured .322" diameter,..close enough.
I stuck the bullet in the lathe and cut it down to .585" length, then loaded it butt forward in the shortened 32-20 case. The shortened bullet weighs 115 grains. The Yugoslavian bullets are more or less a boattail design and the tapered tail section of the bullet, when loaded forward, makes a tidy truncated cone, cup point projectile for the .310 Cadet.
I was a bit concerned about shooting a jacketed bullet with exposed lead now on both ends, but the bullet jacket is rolled over and crimped around the core at the base (now the nose) of the bullet, and there was another ring .4" up from the base where the jacket had been crimped into the core. Because of this, I doubted that the Cadet round would generate enough pressure or velocity to separate the jacket from the core.
After recovering the fired bullet, I discovered that it demonstrated no sign of core separation. In fact, except for the engraving of the rifling, the bullet demonstrated no distortion at all. The thick jacket of the military bullet will probably cause them to perform like solids at any velocity the .310 cartridge is capable of producing.
I loaded a cartridge with 4 grains of Unique and fired it into a stack of magazines just to test its function. The load gave a modest report and didn't penetrate very far, but the test was successful in proving that full diameter. 322" bullets can be used in my Martini with no need for a heel.
Now that that's been established, I'm looking forward to working up some loads with WW296 to see what this bullet is capable of from the little rifle.
The .310 Cadet cartridge was designed to use a heeled bullet of .323" diameter with a .310" heel.
Just out of curiosity, I decided to insert a .322" diameter "O" buckshot in the mouth of one of the trimmed cases to see if it would chamber,...and was surprised to find that it did!
The outside diameter of the mouth of the cartridge measures .334 after it's expanded by the seating of the .322" ball, yet the cartridge readily chambers.
This convinced me that I could use heel-less, full diameter bullets in my cartridges and make the loading process as simple as for any conventional modern cartridge.
I started digging around for any bullets I might have on hand which matched the groove diameter of the Martini and came up with some old Yugoslavian military surplus cartridges in 8mm Mauser. After pulling one of the bullets, I found that it measured .322" diameter,..close enough.
I stuck the bullet in the lathe and cut it down to .585" length, then loaded it butt forward in the shortened 32-20 case. The shortened bullet weighs 115 grains. The Yugoslavian bullets are more or less a boattail design and the tapered tail section of the bullet, when loaded forward, makes a tidy truncated cone, cup point projectile for the .310 Cadet.
I was a bit concerned about shooting a jacketed bullet with exposed lead now on both ends, but the bullet jacket is rolled over and crimped around the core at the base (now the nose) of the bullet, and there was another ring .4" up from the base where the jacket had been crimped into the core. Because of this, I doubted that the Cadet round would generate enough pressure or velocity to separate the jacket from the core.
After recovering the fired bullet, I discovered that it demonstrated no sign of core separation. In fact, except for the engraving of the rifling, the bullet demonstrated no distortion at all. The thick jacket of the military bullet will probably cause them to perform like solids at any velocity the .310 cartridge is capable of producing.
I loaded a cartridge with 4 grains of Unique and fired it into a stack of magazines just to test its function. The load gave a modest report and didn't penetrate very far, but the test was successful in proving that full diameter. 322" bullets can be used in my Martini with no need for a heel.
Now that that's been established, I'm looking forward to working up some loads with WW296 to see what this bullet is capable of from the little rifle.