Re: When to turn
Thank you very much for the replies. Sorry for not providing more info. boomtube, you really put my mind to rest, I will turn before, because then the fireforming shot will centre the case neck in the chamber. Also, I thought that now they have nice clean inside necks and will not interfere with going onto the turning mandrel.
I have been reloading for a long time; I have just never turned any necks. I have no experience turning necks. For this build I am going with a relative tight neck camber so that I can clean up my necks to provide more consistent neck tension when seating my bullets. I load many rounds by hand with an arbour press and Wilson dies and I'm finding too much variance in seating pressure. By the way, K&M make an arbour press with a pressure indicator. I am convinced that these variations are due to inner none concentric case necks because I do have case neck wall differences per case and I'm using Wilson bushing dies (without an expander button).
If you have none uniform case necks, and only size using a bushing die, you are inevitably inducing none circular case necks. The answer to this is to use an expander button. Out of personal preference I don’t like expander buttons. So my answer to the problem is to build a tight neck (.003" clearance total) chambered rifle and turn the brass.
The rifle is built on a Surgeon SA repeater with Badger bottom metal, a 24" Kreiger 1:9.5" twist #5 contour SS barrel. The reamer is made by Dave Kiff at Pacific Tool and Gage, it's set up for .284Win WW brass with a .317 neck and .090 freebore. My WW brass with loaded rounds measure .314 to .316, I'm going to turn them all to .314, and plan on using a .312/.313 bushing.
Remember that turning necks removes material, making them thinner and more prone to splitting. As mentioned here, excessive neck clearance to chamber will make a “sloppy fit”, and also weaken your case through excessive cold working of the brass through sizing. The .284 case is ideally suited to remove a thou or two as it's some pretty hefty stuff.
Last edited by heikki02003; 02-12-2009 at 01:19 PM.