Neck bushings for 6 ppc

[wmdron]

In an earlier post I told about acquiring a Cooper model 21 in 6mm ppc and thanks to the members on this forum I was able to learn that the rifle has a 12 twist and a .272" neck. In addition I was given lots of good advice and as you probably have guessed by now I am back for some more. I have been doing quite a bit of reading and video watching and of course I read the article on this site first. I ordered some Norma brass thinking to do away with fire forming etc. thereby saving myself some time and quite frankly I want to get out and shoot this thing ! Anyway, I have learned that Norma brass is thinner than Lapua and has a .265" neck at the pressure ring with a flat base 6mm bullet seated. My rifle has a .272" neck, if I correctly understand what's going on here, when I fire my rifle using a"Norma" brass bullet the case neck will expand to .272" (the rifles neck) and then spring back a bit maybe to .271" or .270". It looks to me that I will have to resize this neck down to about .264" with a bushing that size, assuming that .001 is enough neck tension. My questions are; can I do this all at once with a .264" bushing or should I do it in stages ? And is this amount of sizing (possibly .006") to the neck going to work the brass too much and cause brass failure prematurely, I suspect it will. Maybe then I would be better off with Lapua .220 Russian. Feel free to correct all my assumptions and to offer any advice and any critique you feel I should hear. Whew, Sorry for being a p.i.t.a., Ron

 

[bozo699]

In an earlier post I told about acquiring a Cooper model 21 in 6mm ppc and thanks to the members on this forum I was able to learn that the rifle has a 12 twist and a .272" neck. In addition I was given lots of good advice and as you probably have guessed by now I am back for some more. I have been doing quite a bit of reading and video watching and of course I read the article on this site first. I ordered some Norma brass thinking to do away with fire forming etc. thereby saving myself some time and quite frankly I want to get out and shoot this thing ! Anyway, I have learned that Norma brass is thinner than Lapua and has a .265" neck at the pressure ring with a flat base 6mm bullet seated. My rifle has a .272" neck, if I correctly understand what's going on here, when I fire my rifle using a"Norma" brass bullet the case neck will expand to .272" (the rifles neck) and then spring back a bit maybe to .271" or .270". It looks to me that I will have to resize this neck down to about .264" with a bushing that size, assuming that .001 is enough neck tension. My questions are; can I do this all at once with a .264" bushing or should I do it in stages ? And is this amount of sizing (possibly .006") to the neck going to work the brass too much and cause brass failure prematurely, I suspect it will. Maybe then I would be better off with Lapua .220 Russian. Feel free to correct all my assumptions and to offer any advice and any critique you feel I should hear. Whew, Sorry for being a p.i.t.a., Ron

Ron,
I could tell you my thoughts on it but why don't you do yourself a favor and P.M Boyd Allen he is a authority on the 6ppc and very very good at explaining himself, I am not sure but I think he posted on your thread on your rifle, hope this will be of some help.
Wayne.

 

[wmdron]

Wayne thanks for your reply and I would be interested in your take on this. I would like to hear from Mr. Allen on this but being a newbie I am not sure how to go about P.M. ing him.

 

[bozo699]

Ron,
I sent Boyd a p.m asking him to come help you, am sure he will but if not I will help you but I am loading for a match right now, later my friend.
Wayne.

 

[wmdron]

Thanks Wayne, Boyd sent me a PM. Ron

 

[Hammer47]

Ron........ .272 is commonly refered to as a "no turn" neck. If memory serves, the Lapua brass is about .014 neck thickness. Add the bullet diameter plus the neck thickness on both sides and you should have a loaded neck diameter of .271 requiring a bushing of about .269 or .268 depending on how much neck tension you desire.

The thickness of the Lapua brass will be MUCH better as there will be less expanding and "working" of the brass in your chamber.

Congrats on your choice of the 6PPC as there is no finer accuracy cartridge to be had. It is my "go to" choice out to 300 meters and in the calm will run with the 6BR at 600. You will really like this little accurate cartridge.

Gary

 

[wmdron]

Thanks for the info Gary, I believe you are correct in that Lapua is the better brass choice and that .272 is a no turn neck. After getting some much needed advice from forum members like yourself and Boyd Allen my plans now include Lapua .220 russian brass an arbor press and wilson dies and bushings. Thanks again and if you can think of anything else please tell me, I need all the help I can get. Ron...

 

[Hammer47]

I have brass and all kinds of different dies, bullets, etc. available from a benchret estate I purchased. If you want to save some money contact me by pm.