difference in forming die and FL die

[nilebartram]

what or is there a difference in a forming die and a FL die?

 

[JMayo]

REDDING CASE FORMING DIES | Brownells

Case forming dies are for those who wish to form brass cases from one caliber to another. Most case forming is ...

www.brownells.com

 

[Oso]

The underlying difference is you are attempting to materially change the dimensions of the brass case and not simply resize the brass back to its initial spec dimensions

Full Length Sizing Die is designed to size a brass case back to the designated cartridge dimensions.

Forming Dies are designed to reshape/reform a brass case into a different cartridge (different dimensions). Depending upon the donor brass, it may take several steps to convert a piece of brass from one cartridge to another. For example converting a 220 Russian into a 6PPC or 6.5 Grendel.

In some instances, no special forming dies may be required when the donor brass cartridge is similar to the desired new cartridge. There are a lot of cartridges in the 223 family that only have minor differences, and only require selecting the case closest to the desired new cartridge and running it through the FL sizing die. For example making cases for .222 Remington from .223 Remington (donor brass) is a simple one step process of slowly/smoothly running the .223 Remington case through the .222 Remington FL Sizing die. However, converting .223 Remington into .17 Fireball will takes several steps to shorten the case, change the shoulder angle, and reduce the neck diameter.