Help Needed in Setting up the PMA Expander Die

[South Pender]

I've picked up a PMA expander die body to use with some Sinclair expander mandrels (which PMA says will fit the PMA die body). (I chose the Sinclair expander mandrels because I have Sinclair turning mandrels and plan to use the expander mandrels prior to neck turning.) Unlike with the Sinclair expander die, no instructions came with the PMA die, and so I'm interested in getting advice on setting it up. I'll be using the setup in an RCBS Rockchucker press.

I'm not clear on how to set the die up so that the case neck is fully expanded, but the case mouth is not crushed in the tapered part of the die body. Should the die be screwed in so that the press ram cams over. Also, I'm not clear on how tightly the mandrel should be secured in the die body.

Can anyone lead me through this?

Many thanks in advance.

 

[Dub]

it only needs to go in deep enough for the expander mandrel to go all the way into the neck. No cam over is needed or desired

 

[1bamashooter]

Use a unsized case run the ram up and screw the die down until you feel it touch the case mouth then back off 4-5 turns. The die should be made so it has some play in the mandrel with the cap on it, 21st Century does not sure about PMA but I like a little play in my mandrel just for alignment purposes

 

[McHaggis]

I snug the set screw down to just touch the expander then back it off maybe 1/2 a turn so it has a small amount of play to help it self align.

 

[NorCalMikie]

it only needs to go in deep enough for the expander mandrel to go all the way into the neck. No cam over is needed or desired

And make sure the expander DOESN'T bottom out on the flash hole inside the case.

 

[dgeesaman]

I raise the ram with no case and hold the case up to the side and eyeball the correct depth. As the others have correctly advised, it can’t bottom out anywhere.

 

[D-4297]

^^^^^^^^ Everything they all said . Covered with two blankets .

 

[divingin]

I don't use a full stroke of the handle when expanding. You can feel when the mandrel enters the neck; just another 15 degrees or so of handle arc ensures the mandrel runs past the neck/shoulder junction. You're only concerned with, what, maybe 1/2" of neck?

 

[Robin]

PMA has two expander dies, does the long expander die works for 308 family cases?
What are the most reliable expander mandrels, Sinclair, PTM, 21st, other?