Blackpowder cartridge shooters know the value of compression dies. They create uniform compression, eliminating dangerous gaps in the case. These quality steel dies feature 7/8" x 14 threads, and work in most reloading presses. Dies must be used with a Die Stem of the appropriate caliber.
Compression dies are used to compress the black powder in the cartridge case to a consistent depth.
The die body has standard 7/8 x 14 thread to fit into any single stage reloading press.
The stem threads into the center of the die body and is secured with a nut on the threads that bears against the top of the die body. Stem threads are not calibrated or otherwise marked.
Compression die with stem is the body with one stem that is caliber specific.
The stem (only) can then be purchased in additional calibers or gauges for use in the die body.
If stem setting in body must be maintained exactly, then multiple die bodies would be needed, one for each stem.
Shotgun stems are not sold with a die body and must be purchased as an accessory to a body with stem.
Montana Precision recommends that a compression die be used for black powder cartridge reloading and that a bullet seater should not be used because it can deform the bullet. Instead, the bullet should be seated into the cartridge with finger pressure only.
More information may be found in the following books by Paul A. Matthews
How-To's for the Black Powder Cartridge Rifle Shooter, pn 536706
Loading the Black Powder Rifle Cartridge, pn 505328
Shooting the Black Powder Cartridge Rifle, pn 373394