6XC Donuts

[Jeff Von Rosenberg]

I have a Tubb gun in 6xc. I neck turn my brass to .014 with a 21st century neck turner. After 2 fireings I have developed a donut , however it is below the base of the bullet after seating. Is this a problem? As I understand it, of the base of the bullet is above the donut it should not be something to lose sleep over! Thanks in advance and I hope this isn't a dumb question. JVON

 

[fdshuster]

Jeff: You are right: don't lose any sleep over it. I also develop donuts in my Lapua 220 Russian (6ppc) and 6BR brass, all outside neck turned, at anywhere from 3 to 6 firings.

My answer to the problem has been to spec my PTG chambering reamers so the most used bullets are seated to touch the lands, with the full diameter of the bullet anywhere from .020" to .035" in front of the donut.

Screwed up on one chamber that had zero freebore and the bullets were contacting the donut, so had my gunsmith use a throating reamer to add .060" to the throat length, and it worked out fine.

 

[Nomad47]

I used a throating reamer on my two 6XCs to make sure the bullets were seated in front of any donuts. I'm on my fourth loading on some of my 6XC brass and I don't know if I have donuts - don't care, either.

 

[Dave L Kiff]

For years folks have sent in dummy rounds and they most always have me make the reamers to touch the lands. I am starting to think in some designs we should touch and add length even if it is only .015 , what do you think ?