After getting a 17 mach IV match barrel for my contender, I had to learn to turn necks properly. The only other necks I had turned before were for my 510 whisper. I merely mounted the brass in a lathe chuck and the neck in the live center. This resulted in a slight variance in neck wall thickness, but since it was a 50 cal cases with a .013" thick neck wall, I lived with it.

However this is no good for a 17 mach IV. I made a mandrel with a thickness of 0.173". This made a tight fit on the sized case neck. I did not support the cases body at all during the turning of the neck. All of my cases had lots of runout after sizing, but only holding the neck kept the body from interferring with a good neck cut. I was able to turn the neck to within about .0005" variance on the neck walls.

Am I on the right track? Thanks.

Ranb

I drive by a good-looking blonde...

Ranb,
Yes, that is as good a way as any when turning on the lathe. You don't want to support the body since to do so may deflect the mandrel. Especially in such a small caliber. Regards, Bill.

[ 06-15-2002, 03:44: Message edited by: centerpunch ]