RCBS Trim Die use

CowboyBart

Sergeant
Full Member
Minuteman
Jun 14, 2007
501
21
North West WY
A friend handed me some 348 cases and dies for me to reload for him. In the die set was a trim die that you run the case up into.
How do I use this die??
Do I lube the case??
Will a file damage the top of the die??
With the die being hardenerd will the die ruin my file??

Wish he would have given me a Lee trim stud and holder - that system is idiotproof!!