December 2nd, 2013

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

When neck-turning cases, it’s a good idea to extend the cut slightly below the neck-shoulder junction. This helps keep neck tension more uniform after repeated firings, by preventing a build-up of brass where the neck meets the shoulder. One of our Forum members, Craig from Ireland, a self-declared “neck-turning novice”, was having some problems turning brass for his 20 Tactical cases. He was correctly attempting to continue the cut slightly past the neck-shoulder junction, but he was concerned that brass was being removed too far down the shoulder.

Craig writes: “Everywhere I have read about neck turning, [it says] you need to cut slightly into the neck/shoulder junction to stop doughnutting. I completely understand this but I cant seem to get my neck-turning tool set-up to just touch the neck/shoulder junction. It either just doesn’t touch [the shoulder] or cuts nearly the whole shoulder and that just looks very messy. No matter how I adjust the mandrel to set how far down the neck it cuts, it either doesn’t touch it or it cuts far too much. I think it may relate to the bevel on the cutter in my neck-turning tool…”

Looking at Craig’s pictures, we’d agree that he didn’t need to cut so far down into the shoulder. There is a simple solution for this situation. Craig is using a neck-turning tool with a rather shallow cutter bevel angle. This 20-degree angle is set up as “universal geometry” that will work with any shoulder angle. Unfortunately, as you work the cutter down the neck, a shallow angled-cutter tip such as this will remove brass fairly far down. You only want to extend the cut about 1/32 of an inch past the neck-shoulder junction. This is enough to eliminate brass build-up at the base of the neck that can cause doughnuts to form.

K&M neck-turning tool

The answer here is simply to use a cutter tip with a wider angle — 30 to 40 degrees. The cutter for the K&M neck-turning tool (above) has a shorter bevel that better matches a 30° shoulder. There is also a 40° tip available. PMA Tool and 21st Century Shooting also offer carbide cutters with a variety of bevel angles to match your case shoulder angle*. WalkerTexasRanger reports: “I went to a 40-degree cutter head just to address this same issue, and I have been much happier with the results. The 40-degree heads are available from Sinclair Int’l for $13 or so.” Forum Member CBonner concurs: “I had the same problem with my 7WSM… The 40-degree cutter was the answer.” Below is Sinclair’s 40° cutter for its NT-1000, NT-1500, and NT-4000 neck-turning tools. Item NT-3140, it sells for $12.95. There is also a 40° cutter for the NT-3000 tool, item NT-3340 ($13.95).

Al Nyhus has another clever solution: “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 forward 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.”

* 21st Century sells carbide cutters in: 15, 20, 21.5, 23, 25, 28, 30, 35, 40, and 46 degrees. PMA Tool sells carbide cutters in: 17.5, 20, 23, 25, 28, 30, 35, and 40 degrees.

Permalink Bullets, Brass, Ammo, Reloading 6 Comments »
May 2nd, 2011

Gear Review: PMA Neck Turning Tool

The PMA Neck Turning Tool, review by Danny Reever
PMA Tool was founded by Matt Harris and Pat Reagin, two former employees of Fred Sinclair. They both worked their way through college working for and designing tools for Sinclair Int’l. They now have branched out on their own and are offering some unique tools for the reloader.

PMA Neckturner Neck Turning Tool

I, like many other shooters out there, would sooner take a beating than change the settings of my neck turner. Many shooters even go out and buy a separate neck turner for every caliber — just so they don’t have to adjust the settings. Most of you know what it’s like, you ruin half dozen cases (or more) getting your neck turner just right, and if you change it the chances of getting it back to where it was are practically nil. Let me be the first to tell you those days are over! Like many of you, I first saw the PMA Neck Turning Tool in an advertisement on this website’s home page. It’s hard to miss, blue anodized finish with the large PMA logo on the body.

PMA Tool Moves the Mandrel, Not the Cutter Tip
From PMA’s website I learned that this turner does NOT use a coarse or fine drive screw to move the cutter towards or away from the mandrel. Nor does the PMA tool move the mandrel on an eccentric (another method of cutting depth control). The PMA tool does something very different. PMA’s Model A Neck Turning Tool simply adjusts by moving the mandrel toward or away from the stationary cutter with an 80 TPI drive screw with 60 indicating marks. Each mark moves the mandrel .0002″ (two ten-thousandths). I found, if you stop between the marks, .0001″ isn’t out of the question. It’s such a smart arrangement, I wondered “why didn’t anyone think of that before?”

Use PMA, 21st Century, or Sinclair Int’l Mandrels
My interest now piqued, I contacted Pat Reagin for one of the PMA tools. Pat suggested that I also use PMA’s stainless expander and turning mandrels since they have put a lot of effort to get them exactly right. I might mention that the 3/8 shank stainless or carbide mandrels from 21st Century or Sinclair Int’l will work also. PMA does have carbide turning mandrels in the works — a nice upgrade for those of you who turn lots of cases at one sitting. I personally didn’t encounter any unnecessary heat build-up with the stainless mandrels only turning 10-20 cases at a time. Considering that carbide mandrels run about $40.00 compared to $7.95 for stainless, it’s nice to save a couple of bucks when you can.

Cut-Depth Settings Can Be Dialed “Dead-On” (Even after Caliber Changes)
Upon receiving the PMA tool I immediately went to my reloading room to set it up for turning some culled .308 Lapua brass — to clean it up 75% for a no-turn chamber. I followed the directions included with the turner and it was a snap to set up. After turning a few of the .308s I made note of my setting and changed both mandrels to 6MM to turn some Lapua 6BR brass for my .269″-neck chamber. Again the change went smooth as silk and I was turning the 6BRs in no time for my preferred loaded neck diameter of .26730″. I then decided to take the leap of faith and change back to turning the .308s after making note of the 6BR setting. That worked, so I then again switched back again to the 6BR setting — again with success. I have gone back and forth (between calibers) numerous times in the last couple of weeks. Each time I easily returned to my caliber-specific settings and I did not ruin a single case in the process. Without sounding like I’m gushing here I must say this is the nicest neck turner that I have ever used. The adjustments are so easy and repeatable “Even a cave man can do it”!

If, like me, you absolutely hate setting up neck turners, for fear of losing your settings, you owe it to yourself to give the PMA Model A neck turner a try. I think you’ll be impressed. The PMA Neck Turning Tool costs $95.95, complete with one carbide cutter with your choice of 30° or 40° shoulder angle.

Disclosure: Danny Reever is a Forum Member. He received no “freebies” or compensation. PMA Tools advertises on AccurateShooter.com.

Permalink Gear Review, New Product, Reloading 3 Comments »