I'm building a 6br, on a reworked rem action, hart brl. Told the smith I wanted a .272 neck, and would buy a new reamer for .272 neck, he said he would take care of it. Picked it up today and he says its a .270 neck and that's what I want??? Also said that I can use Lapua brass, no problem. I also ordered new dies for 6br norma and he got me some redding 6br rem dies. He said that 6br. rem and 6br. norma are the same now and don't worry. My new Lapua 6br norma brass mic's .269, he says just load it and shoot it, he does it all the time, no problem. Can I trust him, or should I get a new reamer in .272 and a new smith?? He gave me a fired round from test firing, and it was rem 6br.brass and fired it was .269?? I thought that 6br rem and 6br norma were not the same. Am I wrong??
.270 neck
- Thread starter nobovine
- Start date
nobovine
the neck on a loaded RP 6MM br measures .269 to .2695
the neck on a loaded Lapua measures .270 to .2705
the neck on a loaded Norma .269 to .2695
this is on some cases that i have.
the cases .200 from the head measure
RP .463/.4635
Lapua .468/.4685
Norma .467/.4675
What brass are you planing to use in this rifle?
How much does it measure at the pressure ring?
as you can see from the measurements, for a custom chamber you need it for a brass or two. IMHO the neck is too tight for anything but RP brass, unless you neck turn. If the pressure ring area is cut for RP brass, I don't think you can chamber Norma or Lapua brass.
Glenn
the neck on a loaded RP 6MM br measures .269 to .2695
the neck on a loaded Lapua measures .270 to .2705
the neck on a loaded Norma .269 to .2695
this is on some cases that i have.
the cases .200 from the head measure
RP .463/.4635
Lapua .468/.4685
Norma .467/.4675
What brass are you planing to use in this rifle?
How much does it measure at the pressure ring?
as you can see from the measurements, for a custom chamber you need it for a brass or two. IMHO the neck is too tight for anything but RP brass, unless you neck turn. If the pressure ring area is cut for RP brass, I don't think you can chamber Norma or Lapua brass.
Glenn
Forum Boss
Administrator
With Lapua Brass acquired 3 mos ago, with a Scenar 105 seated, my dimensions are:
at Mouth: .269"
Middle of neck: .2685"
Neck-shoulder junction: .271"
This is with inexpensive calipers, so figure possible error of about .0005". I've also measured brass wall variances up to about .001" with this lot of brass.
I think the .270 chamber might work, but you may have to turn the last 1/4 of the caseneck, where it swells near the neck-shoulder junction.
at Mouth: .269"
Middle of neck: .2685"
Neck-shoulder junction: .271"
This is with inexpensive calipers, so figure possible error of about .0005". I've also measured brass wall variances up to about .001" with this lot of brass.
I think the .270 chamber might work, but you may have to turn the last 1/4 of the caseneck, where it swells near the neck-shoulder junction.
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