When do you use the F&T dies? What if any are the advantages?

Thanks.. BP...

The name helps tell the story. A form and trim die is used when making one cartridge case out of another. For example, making 30 Herrett cases out of 30-30 cases involves such a die. The 30-30 case is pushed into the die, forming the body, and the excess length now sticking out of the top of the die. A fine tooth hacksaw is used to trim the excess length. The top of the die is flat and specially hardened for wear resistance.

Makes sense. Thanks for the layman terms.

BP...