Comments on: Tool Tip: Optimize Your Cutter Angle for Improved Neck-Turning

By: Kent

Kent — Wed, 04 Dec 2013 15:56:10 +0000

I do a lot of case forming and try to turn the necks at the largest caliber possible (.30 is best) using a bit with a radius as opposed to an angle so it blends in, then reduce the neck down to the desired caliber. Of course, you have to experiment with scrap cases to see what ends up at the target finished neck wall thickness. The bonus is you end up with a neck wall thickness that extends up the shoulder. No cutting anxieties, and the finished product is doughnut-proof.

By: Pat Reagin

Pat Reagin — Tue, 03 Dec 2013 17:56:31 +0000

We also make a 25 degree cutter and can do custom angles or radius on request for a small additional fee.

By: Rick B

Rick B — Mon, 02 Feb 2009 01:24:12 +0000

Al Nyhus’ procedure has been used off and on for years and is tried and proven. Getting the cutter reground to an angle that almost matches the shoulder angle also works well, although I always sectioned a case to make sure that the thickness of the shoulder was still sufficient when setting things up.

The photo of the case neck shows the result of a cutter blade with very little contact area (I think the machinists call it “rike” (sp?)) rather than the smooth finish that is seen when there is a uniform feed rate on a power driven cutter. Some people used to make a cut that was almost to final thickness and then use another turner to make the final cut. That one was often more of a “shaver” than a cutter as it was only going to remove a small amount of material.

I am surprised that no one makes a cutter blade which is set up to handle 30 degree shoulders by now as it is such a common shoulder among accuracy cartridges.

By: Eric Kennard

Eric Kennard — Sun, 01 Feb 2009 21:27:16 +0000

How interesting! I just got my first neck trimmer, a Sinclair 4000. This appears to be a great trimmer. It is very easy to set up and the ten thousanths dial make adjustment easy. However I am having the same problem as Craig. Before I can go past the neck towards the shoulder, the Upper tip of the shoulder bevel starts to make contact. I have considered stoning this edge to a different angle. First I tried making the cut slightly deeper. That helped but it not the answer. A 40 degree cutter looks like the way to go.

By: Al Nyhus

Al Nyhus — Sun, 01 Feb 2009 01:52:07 +0000

The best way I’ve found to get around this problem is to get an extra shell holder and face it off .020-.025 and then run the cases into the sizing die. This will push the shoulder back .020-.025. Then you neck turn down to the ‘new’ neck/shoulder junction and simply stop there. Fireforming the cases by seating the bullets hard into the lands will blow the shoulder foward and the extra neck length you turned by having the shoulder set back will now be blended perfectly into the shoulder.

The results are a case that perfectly fits the chamber and zero donuts.

By: Boyd Allen

Boyd Allen — Sat, 31 Jan 2009 18:18:41 +0000

Rather than guess about excessive thinning at the neck shoulder junction, I find it better to sacrifice a case, and section a turned neck and beyond, down into the shoulder, so that I can see what is taking place. I use a cordless Dremel tool with a reinforced abrasive wheel for this job, making sure to wear a paper mask and glasses to keep the brass particles, (that are sprayed directly at my face as the cut is made), from being inhaled or getting in my eyes.

In my experience, if the cut on the shoulder is even all the way around, and not deep it shouldn’t be a problem. On the other hand, if my necks were as rough as those shown, I would have to investigate as to the cause, or at least do a little power driven clean up with 0000 steel wool.

Sometimes when the cutter is too narrow where it is actually cutting brass, a little hand work can broaden it out and result in a smoother cut. I have improved results with more than one brand of turner that way.