Turning necks... starting point

[P1ZombieKiller]

I need clarification on neck turning. I am building a .269 neck 6BR. so the necks need to be trimmed up just a bit. I have purchased a few hundered rounds of Lapua brass on this site of various stages of life, ranging from new in box, to shot many times. right now I have 200 at 3x fired, and 300 new in unopened box. I already have an RCBS neck turning set up but I have no 6BR dies,other than the Redding comp seater with micrometer)

http://www.midwayusa.com/viewproduct/?productnumber=516187

here is my question.... I need to make sure that the necks are really a perfect circle before I start to turn them. right? Do I buy a die to do that? what is it called? I searched for 'Universal sizing die' and found nothing.

How do I get the necks in a perfect circle so I can turn them to .012 and KNOW that one side is not a little bit off the mandrel, and I'm actually digging in to deep? Some of the new brass have necks that look like they are new brass,one side dimged in), but the 3x fired brass looked to be perfectly round. I have turned a few of them, and they seem to be going smoothly, but I'm worried about the new brass.

 

[jr600yd]

Wes,
What you want to do isn't as difficult as you think. Best advice is to call Sinclair Int www.sinclairint.com 1-800-717-8211. Explain what you want to do and they will take care of you. You will need a die and the correct size mandrel. Once the necks are run over the mandrel all defects are transfered to the outside of the neck. Now you can neck turn the cases and have concentric necks.
Good shooting

Jim

 

[KevinL]

P1Z as already posted you realy need to size the brass wether full lenth or neck size
The mandril holding the decappijg pin will uniform the inside of the brass to proper size then you can turn what you need off the out side of the case.
mike as you go load a dummy round with bullet and check in chamber as well as mike for proper clerance.
I have a 3 die set of 6 br that I just bought that I dont nead if you are interested Redding
Good Luck Kevin