Does anyone have experience using Lee Collet dies for resizing the neck of 257 Roberts Ackley Improved?

I use Lee collet dies for standard 223 and 6mm to reload for 223 AI and 6mm AI. They work fine and the bonus is that I have never had to trim the brass.

Thanks

If, by chance the AI changes the configuration of the shoulder/neck area a bit and you need the die to size "higher" on the neck you can do so by adding a washer on top of the shellholder.
I actually have some collet dies that are worn to the point I have to do this even on the caliber they were intended for.
The washer will "activate the collet" before the shell is totally raised in the die...thus it will do the sizing higher on the neck.

good info, thanks Kraky

I use the 30-06 collet die for my 30-06 AI. Produces 1/2 MOA ammo.