6 BRA Reamer - Thoughts?

[samb300]

I'm thinking about a new barrel for next season, and am leaning towards a 6 BRA. I don't have any brass on hand, so was wondering if anyone that shoots a 6 BR/BRA/Dasher with Lapua brass could help?

I'd plan on a no-turn chamber, so was thinking of 0.272" neck diameter. Then a 0.104" freebore for 105-class bullets? The other question I have is what effect the shoulder diameter has. Since this will be for a PRS-style match application, I don't want a bench rest chamber. One of the more BR-oriented reamers has a 0.461" shoulder diameter and a tight 0.268" neck, whereas another reamer has a 0.463" shoulder diameter and a 0.272" neck.

Thanks for any help, especially if you can measure the neck diameter of a loaded round, or give me any feedback on your experiences with a 6 BR variant.

Sam

 

[Sheldon N]

Loaded round Lapua neck at .2675 to .2685 so a 272 or 273 chamber is good for no turn PRs shooting. .463 shoulder is too fat, most sizing dies will give you .458 so too much working of the brass. I’d lean towards .460 or .461 shoulder. Base diameter at the .200 line also matters. My experience is that .4708 is a bit small, my chamber is .4715 and both Forster and Whidden dies will work.