Comments on: Neck Tension 101 — It Ain’t As Simple as You Think

By: Joe Regina

Joe Regina — Tue, 13 Sep 2016 02:36:06 +0000

Neck tension is by far the toughest one, of the Holy Trinity of Precision Handloading, to crack and I’ve been working on it for nearly a year.

I agree with the factors mentioned in the article above. However, I would like to point out that focusing on the bushings to get the right neck tension is inherently an inaccurate path. Bushing affect the outside of the case neck and a .001 change in size has a big impact that causes seating pressure (measured by the hydro press) to jump by 20-30 pounds. So it my opinion that this is the wrong way to go about it. Its like a meat cleaver and what we need is a scalpel.

What really matters is not the outside diameter of the neck, it is the inside diameter that is critical to neck tension, that’s what touches the bullet.

If you think about it, it is easier to affect and control tension by expanding necks with a mandrel. I squeeze them down with a FL sizing die and then expand them with a mandrel. I can vary the size/diameter of a mandrel by .0001 thus giving me very specific amount of tension. I can go from 5-10 lbs range to the 15-25 lbs and systematically experiment to see which works best.

The trick is keeping it there because mandrels, like everything else, wear down with use. Even tool steel (D2) starts changing slightly after 800+ cases Another important factor is to make sure that the mandrel is perfectly straight and without “float”.

I have been working with a tool and die maker and I am confident I have finally cracked the third and last of the Holy Trinity.

There are ways to defeat each of the factors mentioned in the article but solving 3 out of 8 or 7 out of ten won’t work. They all have to be solved and assimilated in a process that uses the right tools and methods consistently, not an easy thing to do.

By: Russ

Russ — Tue, 19 Jan 2016 21:15:05 +0000

why care what the neck OD is?.. would it not make more sense to measure the ID of the case, then it dont matter how thick the walls are, use a collet die like the LEE, resize to .003 or whatever less then the bullet dia. and be done? way less wear and tear on the brass over a bushing die

By: Jerry

Jerry — Fri, 06 Nov 2015 14:16:37 +0000

One more point, if you tumble [with stainless media], try using a liquid car wash and wax on the final rinse of the brass. This will leave a small amount of residue inside the neck. I also dip the necks in the imperial graphite jar. This eliminates any grabby-ness.

By: LWM

LWM — Fri, 06 Nov 2015 00:02:04 +0000

“but also at how your brass has changed (work-hardened) with time,”

just great– how do I do this?

By: Guy

Guy — Thu, 05 Nov 2015 18:51:14 +0000

Terry, I don’t known how etched in stone it is but generally light tension is preferred.

By: nick brungard

nick brungard — Thu, 05 Nov 2015 17:27:43 +0000

Im no world record holder, my experience is directly related to results on paper shooting prone from a prs type rifle so take this how you want. I could not put improved results on paper by monitoring neck tension. No matter how bad i wanted to feel like all my studying and experimenting gave me an edge. The most important thing i took away is that to little neck tension will leave the bullet in the lands if you try to unload a chambered round. I think theres more payoff getting each powder charge perfect.

By: Terry Balding

Terry Balding — Thu, 05 Nov 2015 14:11:45 +0000

Great article! Has anyone proven that a specific neck tention produces greater accuracy?

By: Ordell

Ordell — Thu, 05 Nov 2015 06:42:42 +0000

This topic always makes me think about crimping. I know most believe that it hurts accuracy but when I’ve tested crimps sometimes it helps. Granted most of the time in my tests it doesn’t but that sometimes is worth looking at. Sometimes.

By: Jerry

Jerry — Thu, 05 Nov 2015 02:47:07 +0000

You cant rally do this subject without addressing concentricity, you can have uniform tension but I think concentricity will come into play and effect the results more than the uniformity of neck tension.

By: Mark C

Mark C — Wed, 04 Nov 2015 23:34:19 +0000

Mike: Interesting comments. How did you come to your opinions? If you claim the article was “bad” information, then how did you get your “good” information? Do you have equipment to exactly measure the amount of frictional force required to pull a bullet out of the case? Do you have some sort of equipment to measure what happens to the case neck as the powder burns and tens of thousands of pounds of pressure are released? Have you conducted experiments with control groups to verify your conclusions? I am a bit of a science geek so I am very, very interested in the facts and methodology that support your statements. The extremely complex physics of what goes on during the micro-seconds of primer ignition to the bullet out of the barrel are virtually impossible to exactly know. So I was wondering if you were basing your statements on other articles you have read, personal experience, or actual scientific empirical data. Thanks for the clarification.