Here is a really good read. With some cool twists with pictures.
If you have ever tumbler 40S&W ,9mm and 45ACP together you will find out those cases fit snugly inside of each other.
Swage 240-gr .44 Mag Jacketed Bullets from .40 S&W Brass Using 7x57mm Mauser Die
I may have posted this before, but this process works, and combines several skills you already have to produce jacketed 240-grain .44 Remington Mag bullets from pure lead 40 caliber slugs and .40 S&W spent brass. Watch Mannyca's video at https://www.youtube.com/watch?v=TC2Ad3k3kgg for exact...
castboolits.gunloads.com
If you have ever tumbler 40S&W ,9mm and 45ACP together you will find out those cases fit snugly inside of each other.