My 17 Mach IV brass necks are too thick causing high pressures. How do others reduce this thickness by neck reamer or outside neck turning or both. thanks for the help. Twyman

Twyman--This is just an educated guess on my part, but I think your best bet to get the same thickness on the necks all the way around would be to go with an outside neck turner. I would think the inside neck reamer would be hard to get running down the neck so you get the thickness on all 360� of the neck close to the same.

Outside neck turning is almost always the preferred method. It's no fun, but once you are setup, it goes fairly quickly.
You may still need the neck reamer to remove any possible "doughnut" that may exist inside at the neck/shoulder junction. This may not be seen until the turned cases have been fired.
Great 17 cal reading/info over at saubier.com forum.

I outside neck turn my 221 Fireball cases before necking down in a 3 step form die set. Perfect!

You're not making them out of .223 cases instead of .221FireBall cases, are you?

Outside neck turning is the way to go. The necks will be concentric.

George