Ream or Neck Turn? Concentricity


PDA






Lovesbeer99
September 30, 2011, 01:48 PM
I see that I have a choice to ream the inside of my neck before I resize the case or to turn the neck after resizing.

Does anyone have any experience with this? Which is better?
Also can you recomend a good gauge to measure concentricity?

If you enjoyed reading about "Ream or Neck Turn? Concentricity" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
brickeyee
September 30, 2011, 02:11 PM
Reamers are very good at following holes.

They are not good at uniforming the thickness of the material around the hole.

Turn the necks if you want better concentricity.

All a reamer will do is make a larger hole along the same off center axis.

Afy
September 30, 2011, 02:50 PM
If you are not shooting consistently groups of 0.3 << inches at 100 yards you are not going to see any difference with neck turning, reaming, concentricity et al.
It is rumored once you are in the range having a uniform clearance of at least 0.01 in on the neck in the chamber helps improve accuracy. There are some VV sponsored vids floating around with more info.

Walkalong
September 30, 2011, 03:19 PM
I reamed and then turned the necks on my 6 PPC brass, but it was for a tight necked chamber. For standard chambers all you really want to do, if you do it at all, is to turn the neck enough to clean it up. Turn just enough so that 95% to 99% of the outside of the neck is touched by the neck turner.

It may not help any, but then again, it might. There are many variables involved.

Offfhand
September 30, 2011, 04:10 PM
Quoted from above post:
"If you are not shooting consistently groups of 0.3 << inches at 100 yards you are not going to see any difference with neck turning, reaming, concentricity et al."

Ah Cantrare Mon Ami, An experienced handloader/shooter can yield measureable improvement in accuracy by turning case necks for rifles that normally shoot groups considerably larger than .3" I've seen and done it too many times for this to be a debatable issue.

USSR
September 30, 2011, 04:25 PM
My experience has been with neck turning Lake City Match brass. Looks nice and makes me feel good, but still doesn't shoot as good as stock Lapua brass.

Don

243winxb
September 30, 2011, 04:28 PM
Ream if a donut has formed at the neck/shoulder junction. The reamer will be smaller than bullet diameter leaving neck walls thick enough for outside neck turning to the final size.

rcmodel
September 30, 2011, 05:40 PM
One could argue that an unturned neck, even if off-center slightly, fits a typical loose factory chamber better then one that has been neck-turned smaller.
More rattle room after neck turning so to speak.

Anyway, the only really accurate rifle I ever owned that had to do anything to the case necks was a 22-250 I built years ago.

Neck thickening was it's problem, and I had to neck ream occasionally to get enough case clearance for it to expand and release the bullets.
Would neck turning have given better accuract then reaming?

Probably, but it was already shooting 1/2 MOA, so how much better could I shoot it?

And a reamer bit for my Herters case trimmer was all I could afford back then anyway.

rc

If you enjoyed reading about "Ream or Neck Turn? Concentricity" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!