Should I neck-turn?

[jray57]

I recently put together a 6XC with a .275 neck chamber. The loaded brass (Norma 6XC) measures .271 at the neck. The gun shoots really well- in the .2"s and .3's which is real good for me. But the bullet is a fairly snug slip fit in a fired case and has a definite stop at the "donut" in once fired cases. Headspace was set on a full length sized case sized in my die and is stiff closing the bolt with one peice of clear tape on the brass ( no ejector in the bolt) if it matters. Incidentally a fired case neck measures .274 which confirms the .275 neck chamber. I am shooting Sierra 107 MK"s on top of H-4350 at 39 gr with no pressure indications. I am concerned about the slip fit in a fired case and also with the "donut" as I am having a collet die made and am wondering how the "donut" may affect the mandrel/sizing? What do you think?

 

[billmo]

Jray, if you have a loaded round measuring .271 and your fired round is at .274 you have plenty of room for expansion. I don't think you will gain anything from turning your brass unless you can detect some inconsistances in your neck wall thickness and maybe a slight clean up is all you need. I really don't think turning the brass necks will make your donut go away. K & N makes a tool to get rid of the donut. I hope this helps. Bill

 

[artbosco]

K & N makes a tool to get rid of the donut.

The link: http://www.kmshooting.com/catalog/neck-turner-tools/carbide-cutting-pilot.html

 

[jray57]

I am not so much worried about the donut as regards bullet seating because the bullet base is not as deep as the donut when the bullet is seated. What I am a little concerned about is how the thicker portion of the neck will affect sizing by the collet die. I don't know if the die sizes all of the neck or if it leaves a little of the base of the neck unsized. Any one who uses a collet die on cases with a donut could help me with this one.

 

[ReedG]

Jray, there is no positive value from the "donut". If left, it also reduces the vortex area for the burning powder and gases. My Lee Collet dies size darned close to the entire neck and a donut would interfere for sure.