Necking down 222 Mag Cases

22hipower

Recently acquired a '60s Ackley/O'Brien marked 17 Magnum built on a Sako 461 action. From what I've read, that should be the 222 Rem Mag necked down to 17. I know I need to get some cerrosafe and check the chamber to be sure. Ok, so I've been trying to neck down 222 Rem Mag brass. Too cheap, so far, to spend the $160 or so for special reduction dies and another $160 for the 17 Mag dies. Had the great idea of using a Hornady 17 cal neck sizer die to neck down to 17. However, that resulted in collapsing the shoulder. So, thought maybe if I tried a 20 cal neck sizer first and then used the 17 that might do it. Unfortunately the 20 cal die collapsed the shoulder too. In both cases I lubed the case neck before sizing. Any suggestions on what I'm doing wrong or is the solution to spend the $$ and get the dies advertised for the purpose? Downside of that is there is a 90+ day waiting period too in addition to the steep price.

20gabob

Try annealing the case necks before you go to size them down. Cases are probably work hardened and by annealing will soften the case necks. they will harden back up by resizing them.

zimmden

Anneal first. If you have or can borrow a bushing neck sizing die for 222 mag or even 223 or 222 or 204 you can use progressively smaller bushings to reduce necks. Most 222 mag brass has thick necks. You probably need to neck turn them to about .010 before annealling. Sizing down about .002 to .003 at a time with lube should keep the shoulder from collapsing.

oneoldsap

I don't believe you will have any success necking down with a neck sizing die . There is nothing to support the case and it will collapse every time ! IMO

22hipower

Thanks much for the advice. I'll try annealing the brass but suspect I'll be making an investment in forming dies soon.