ABCs of Neck Turning — Here is How It’s Done

On our main AccurateShooter.com site, you’ll find an excellent article by GS Arizona on the Basics of Neck Turning. If you’re new to the neck-turning game, or are just looking for good tips on improving your neck-turning procedures, you should read that article. Below we offer some highlights and photos from the article, but you’ll need to read the whole story to view all the illustrations and follow all the procedures step by step.

Why Should You Consider Neck Turning?
Let’s assume that your rifle doesn’t have a tight neck chamber that requires neck turning; if you have a tight neck chamber, of course, the answer to the question is “because you have to”. For the rest of us, and that includes the vast majority of Highpower shooters, neck turning isn’t a requirement, but it can be a useful way to bring your ammunition a small but meaningful step closer to that pot of gold at the end of the rainbow: perfection. I’m not talking about a theoretical improvement, but a real one, an improvement that lies in equalizing and optimizing the neck tension of your loaded rounds. Inconsistent neck tension is a real contributor to increased muzzle velocity variance which itself is a significant factor in increased elevation dispersion at long range. So there’s our basic reason for neck turning: to equalize and optimize neck tension in order to reduce elevation dispersion.

The Tools of the Trade
Here you see everything I use and a bit more. The press, a cordless screwdriver (always plugged in, turning is tough on the old battery), a couple of K&M neck turners (one set up for 6mm, the other for .30 caliber) an expander for each size, some Imperial lube, an old toothbrush or two to keep the cutter clean, a handle with a caseholder (for those emergencies when the screwdriver dies and there’s just one more case to go!), steel wool and a tubing micrometer finish the list of tools. Hey, I left the dial calipers out of the picture! They’re always handy, keep them around, but they are useless for measuring neck thickness, so don’t try. I usually use an Optivisor magnifier while I turn necks, very handy for a clear view of what’s happening on the neck.

Expanding the Neck
Put some lube on the inside of the case neck and run it into the expander. Really, this isn’t hard. I prefer to expand each case immediately before turning it as opposed to expanding all the cases and then turning them. Brass is somewhat springy and will tend to go back toward its original size; therefore, by expanding and turning immediately, you are more likely to have all cases fit the mandrel with the same degree of tightness and to get a more consistent depth of cut.

Cutter Adjustment for Cut Depth and Length
All the tools I’ve seen have pretty good adjustment instructions. The only thing they don’t tell you is that you should have five to ten spare cases to get it right initially. Anything of the right diameter will do while you learn, for instance, just use that cheap surplus .308 brass to do initial setup and save the precious .30-06 for when you know what you’re doing. Be patient and make your adjustments slowly; you’ll need to set the cutter for thickness as well as length of cut (just into the shoulder). The depth of cut (brass thickness) takes a bit of fiddling, the length of the cut is generally easy to set.

The Finished Product — A Perfectly Uniform Neck
If you read the whole article, and follow the procedures using quality tools, you should get very good results — with a little practice. To demonstrate, here’s an example of my finished, neck-turned brass. You’ll see there is a perfect, 0.0125″ thick neck. It’s very uniform around the circumference, usually I only see 1 or 2 ten-thousandths variance. Now, with the necks uniformed like this, we can select the bushing size that will give us our preferred neck tension and experiment with various levels of tension, secure in the knowledge that all of the cases will actually have the desired neck tension.