17 Ackley hornet form die question

[JohnJ65]

Hello, I recently picked up a second hand RCBS 17 Ackley hornet form and trim die set with an extended shell holder.

The form die is pretty much self explaining, I think.

My question is for the trim die:
Is the trim die to be used after fire forming to trim to length only, or is it also a second step in the forming process? I was not sure if the form took it to say 20 caliber then the trim die to 17.

Thank you for any help, the directions with the set is not caliber specific.

John.

[SEM]

John, the trim die is intended to use as a length maintenance trim gauge, all though they really often they make a very good form die also, I usually start with a trim die on many cases and then either a form or full length die depending on how severe the change, Trim dies are frequently cheap to buy because most reloaders use other much easier trimming tools, I think I probably have some where near 15 different trim dies probably more

and yes probably in your case form die first then trim die then full length

[20VarTarg]

SEM is correct. The first step is run the brass into the form die. Second step is run the brass into the trim die and trim it off with a file. Then chamfer and debur the brass. Final step is run it into the FL die. Load it up, Fire Form it and you have your brass. It's tedious work but it's a great little cartridge. I fire formed 64 pcs yesterday. Good Luck and have fun.

[JohnJ65]

Okay, I was concerned that if I trimmed before fire forming it may end up too short.

[SEM]

John, that is a real probability, I carefully measure the actual chamber depth and start my brass after forming at .001- .002 shy, cases especially when the body will grow notably in diameter the case will shrink quite a bit, you do not have to trim if the formed case allows the action to close. Still run into the trim die to further reduce the case before full length sizing

[JohnJ65]

Thank you for all of the advise.
John

[20VarTarg]

Originally Posted by JohnJ65

Okay, I was concerned that if I trimmed before fire forming it may end up too short.

On my trim die, the brass is long after trimming. I was thinking about shaving some material off the shell holder but haven't found a reason to because they all chamber just fine. So I left it alone.

[Daryl]

Originally Posted by 20VarTarg

On my trim die, the brass is long after trimming. I was thinking about shaving some material off the shell holder but haven't found a reason to because they all chamber just fine. So I left it alone.

Chambering is one thing, but if a fired case easily admits a bullet as in drops in, then your rifle's chamber is longer than normal. If the case will not easily admit a fresh bullet, the cases are too long for THAT chamber.
Such is life with non-SAAMI or CIP ctgs.(more so CIP as in Europe, it is law there, not just a "suggestion of conformity" as here in NA.