Before you load that nice new cartridge brass for the first time, run an expander mandrel down the case necks. This will iron out dents and provide more uniform neck tension. Chose a mandrel diameter that provides appropriate neck tension.
Lapua brass is so good that you’ll be tempted to just load and shoot, if you have a “no-turn” chamber. However, some minimal case prep will ensure more uniform neck tension. Keeping your neck tension very uniform allows more consistent bullet seating. That, in turn, usually yields better accuracy, and lower Extreme Spread and Standard Deviation (ES/SD). Lapua brass, particularly 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win comes from the factory with tighter-than-optimal necks. Before you seat bullets, at a minimum, you should inside chamfer the case mouths, after running an expander mandrel down the necks. The expander mandrels from both Sinclair Int’l and K&M will both leave the necks with enough neck tension (more than .001″) so you can then seat bullets without another operation. We suggest putting a bit of lube on the mandrel before running it down the necks — but remove any lube that gets inside the necks before seating bullets.
Both Sinclair and K&M Tools make a die body specifically to hold expander mandrels. The Sinclair version, is shown above. This $28.99 unit fits caliber-specific expander mandrels ($9.99) which measure approximately .001″ less than bullet diameter for each caliber. This is an updated “Gen II” design that completely captures the mandrel within the die so the mandrel cannot pull out. It also has an O-ring in the die cap that allows the mandrel to self-center within the case neck. Sinclair now offers three sizes of die bodies for expander mandrels: .17 -.338 Caliber (#749-011-715WS); .357 – .50 caliber (#749-008-843WS), and a special .50 Cal die body for large-diameter 50 BMG presses (#749-009-163WS, $39.99). All Generation II dies are machined from stainless steel and the standard diameter 7/8-14 dies include the Sinclair Stainless Steel Split Lock Ring.
Once you run the Sinclair expander mandrel down the necks of Lapua brass, after you account for brass spring-back, you’ll have about .002″ neck tension*. This will make the process of seating bullets go much more smoothly, and you will also iron out any dents in the case mouths. Once the case mouths are all expanded, and uniformly round, then do your inside neck chamfering/deburring. The same expander mandrels can be used to “neck-up” smaller diameter brass, or prepare brass for neck-turning.
Forum member Mike Crawford adds: “These expanders can also reduce runout from offset seating. Prior to bullet seating, expand the sized necks to force thickness variance outward. With the Sinclair system, the necks will springback fine, and will not be pulled out of center. This leaves plenty of tension, and bullets seated more centered. I do this, even with turned necks, to get improved seating.”
Mandrels vs. Expander Balls on Decapping Rods
If you haven’t acquired an appropriate expander mandrel for your brass, but you DO have a full-length sizing die with an expander ball, this will also function to “iron out” the necks and reduce tension. However, using a die with an expander ball will work the necks more — since you first size them down, then the ball expands them up again. Typically (but not always), run-out is worse when using an expander ball vs. an expander mandrel.
* This .002″ tension is what we have observed with Lapua 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win brass. This might vary with much smaller or larger cases, and of course a different brand of brass might yield different results. If you get too little tension with your current mandrel, you can get a smaller-diameter mandrel from 21st Century Shooting. 21st Century even offers low-friction Titanium Nitride-coated mandrels.
Most of us assume that if we weigh our powder carefully (down to the tenth of a grain or less) we can achieve a uniform powder fill from case to case in our handloads. Weighing does ensure that the weight of the propellant in each case is the same, but is the column of powder the same by volume each time? “Not necessarily” is the answer. An interesting experiment by our friend Boyd Allen demonstrates that the manner in which you place kernels in the case can make a significant difference in the height of the powder column within the brass case.
Using a Gempro 250 scale, Boyd measured exactly 30.6 grains of Vihtavuori N-133 powder. He then inserted this powder in the same cartridge case multiple times. (The case has a fired primer in place.) But here is the key — Boyd used various filling techniques. He did a slow fill, and a fast fill, and he also experimented with tapping and drop tubes. What Boyd discovered was that you can start with the exact same weight of powder (in fact the very same set of kernels), yet end up with vary different fill heights, depending on how you drop the kernels into the case. Look at the photos. Despite variations in lighting, the photos show the same 30.6 grains of powder, placed in the same cartridge, with four different methods.
Using funnels with long drop tubes packs kernels more tightly, creating a shorter powder column. That allows you to get more propellant (by weight) into the case.
Boyd Explains the Procedure Used for his Experiment.
EDITOR’s NOTE: So there is no misunderstanding, Boyd started with a weighed 30.6 grain charge. This identical charge was used for ALL four fills. After a fill the powder was dumped from the case into a pan which was then used for the next fill technique to be tried. So, the powder weight was constant. Indeed the exact same kernels (of constant weight and number) were used for each fill.
Boyd writes: “I used the same powder for all fills, 30.6 gr. on a GemPro 250 checked more than once. All fills employed the same RCBS green transparent plastic funnel. The fast drop with the funnel only overflowed when it was removed from the case neck, and 15 granules of powder fell on the white paper that the case was sitting on. The fast-funnel-only drop with tapping, was done with the funnel in place and the case and funnel in one hand, while tapping the case body with the index finger hard, many times (about 20 fast double taps). My idea here was to “max out” the potential of this tapping technique.
The slow drop with the funnel and 10″-long .22 cal. Harrell’s Precision drop tube, was done by holding the scale pan over the funnel and tapping the spout of the pan repeatedly on the inside of the funnel about 1/3 down from the top, with the scale pan tilted just enough so that the powder will just flow. Many taps were involved, again, to max out the technique.
Again, to be clear, after each case filling, the powder was poured from the case back into the scale pan carefully. You may notice the similarity between the fast drop with the drop tube, and the funnel only with tapping. Although I did not photograph it, fast tube drop and tapping (combined) improved on tapping alone, but only to about half as far down the neck as the slow with drop tube. Due to the endless possible permutations, I picked four and left it at that.
I believe that I can make the rough judgment that the scale pan funnel and drop tube technique, which involved a longer drop period, and probably less velocity at the top of the tube, left more room in the top of the case neck than the slow drop from the measure with the same drop tube. You have both pictures, so you can make the comparison.” — Boyd
Does Powder Column Height Variance Make a Difference?
Boyd’s experiment proves pretty conclusively that the method of dropping a given weight of powder can affect the height of the powder column in the case and the degree of powder compression (when a bullet is seated). He showed this to be true even when the exact same set of kernels (of constant weight) was used in repetitive loadings. This raises some interesting questions:
1. Will subsequent cartridge transport and handling cause the powder to settle so the variances in powder column height are diminished?
2. If significant inconsistencies in powder column height remain at time of firing, will the difference in fill level hurt accuracy, or result in a higher extreme spread in velocity?
3. Is there any advantage (beyond increased effective case capacity) for a tight (low level) fill vs. a loose (high level) fill?
We don’t know the answer to these follow up questions. This Editor guesses that, if we tested low-fill-height rounds vs. high-fill-height rounds (all with same true fill quantity by weight), we might see meaningful differences in average velocity. I would also guess that if you fired 10 rounds that exhibited quite a difference in powder column heights, you might see a higher ES/SD than if you shot 10 rounds loaded with a very consistent powder column height (either high or low). But further testing is needed to determine if these predictions are true.
When developing loads, it is important to know the true internal capacity of your cases, both fired and “as FL-sized”. In particular, when using the QuickLOAD program, it is vital to determine true case capacity. The default case capacity values listed by QuickLOAD may be off half a grain (or more) because brass from different manufacturers can vary considerably in capacity. Case capacity is a very important variable that will affect the pressure of a load and the velocity of your bullets.
To determine the true internal capacity of your cases, first weigh an empty cartridge case, then fill the case with water (all the way to the top of the neck) and weigh the case again. The difference in weight is your H20 capacity in grains. But how do you keep the H20 from flowing out the bottom? When measuring fired, unsized cases, you can simply leave the spent primer in the pocket. However, if you want to measure new brass or “as-FL sized” cases that have been deprimed, you’d have to insert a spent primer to “stem the tide”. Until now that is… 21st Century Shooting sells a great little $5.50 tool that plugs the bottom of the case so you can measure H20 capacity with ease.
When we saw 21st Century’s Primer Pocket Plug we thought “That’s smart — why didn’t someone think about that a long time ago?”. This handy “end-cap” lets you quickly measure multiple new brass cases or deprimed FL-sized cases so you can get an average H20 capacity. The primer pocket plugs are NOT case-specific (they feature an O-ring that fits the pocket). One version will work with all small-primer-pocket cases, while another works with all large-primer-pocket cartridge types. Price is $11.99 for either small-pocket or large-pocket version.
NOTE: If you want to measure H20 capacity on fired, sized brass, but don’t want to shell out the money for the tool (or re-insert a spent primer), here’s a simple suggestion. When you size your case, first remove the decapping rod from the die. Then you can FL-size the case without removing the primer. Of course, you will eventually have to knock the primer out, and that requires putting the decapping rod back in the die and running the case through a second time. To avoid that hassle, the Primer Pocket Plug may be worth the twelve bucks over the long haul.
Product Find by EdLongrange. We welcome reader submissions.
Gear Reviewby Germán A. Salazar, Contributing Editor
Reloading at the range with an arbor press and Wilson dies is my preferred method of load development. I’ve had a chance to test and evaluate the Arbor Press from 21st Century Shooting. I have to say I’m very favorably impressed by it.
An arbor press’ basic function is simple enough: exert sufficient downward pressure on the die to either size the case neck or seat the bullet depending on which die is in use. It isn’t a mechanically challenging function. So why do we use an arbor press and what should be look for in one? Consistent operation, sensitive feel, quality of design and machining are the hallmarks of a good arbor press and this one from 21st Century comes away with good marks in all areas.
For my initial session with the press, I seated 72 bullets in .30-06 cases, another 70 in .308 cases and neck sized a handful of cases (just for evaluation since I prefer to full-length size). The design of the actuating arm, which angles slightly away from the press was very convenient, allowing me to operate it with less jostling of the press because my fingers weren’t bumping into the press head as they sometimes do with my previous press that has the handle parallel to the press head. That’s a nice touch and shows the press was designed by someone who has used these things.
The press uses a relatively light return spring which materially aids the feel of seating pressure. I prefer this to a heavier return spring which would reduce the feel that I really look for in an arbor press. For someone who uses very heavy neck tension this might not be a big concern, but because I usually use 0.001″ to 0.002″ neck tension, the ability to detect small levels of variance in seating pressure is important to me.
High Quality Machining and Parts Finishing
Every part of the 21st Century press reflects careful thought and skilled machining. The knurled wheel for adjusting the height of the press head is a distinct improvement over the plastic hardware store knobs seen on many presses.
The aluminum press head itself is nicely anodized, the steel base well blued and the shaft nicely polished. Even the decapping base (photo at left) reflects careful design as well as precise machining. Overall, the press gives a look and feel of quality and is a welcome addition to my range reloading setup.
Editors’ Note: The designer of the 21st Century Arbor Press has decades of tool-making experience, and he has designed tools for many “big-name” companies. 21st Century stands behind the product with a lifetime warranty for the original purchaser. The Arbor Press is currently offered in four different versions, with two post heights (8.5″ or 10.5″), and two baseplate sizes (small 3″ x 4″ or large 4″ x 5″). Prices start at $94.99 for the 8.5″ post and small baseplate. CLICK HERE for more info.
This review originally appeared in RiflemansJournal.com in 2010. 21st Century Shooting Inc., a site advertiser, supplied an Arbor Press for testing and evaluation.
When developing loads, it is important to know the true internal capacity of your cases, both fired and “as FL-sized”. In particular, when using the QuickLOAD program, it is vital to determine true case capacity. The default case capacity values listed by QuickLOAD may be off half a grain (or more) because brass from different manufacturers can vary considerably in capacity. Case capacity is a very important variable that will affect the pressure of a load and the velocity of your bullets.
To determine the true internal capacity of your cases, first weigh an empty cartridge case, then fill the case with water (all the way to the top of the neck) and weigh the case again. The difference in weight is your H20 capacity in grains. But how do you keep the H20 from flowing out the bottom? When measuring fired, unsized cases, you can simply leave the spent primer in the pocket. However, if you want to measure new brass or “as-FL sized” cases that have been deprimed, you’d have to insert a spent primer to “stem the tide”. Until now that is… 21st Century Shooting has come up with a simple tool that plugs the bottom of the case so you can measure H20 capacity with ease.
When we saw 21st Century’s Primer Pocket Plug we thought “That’s smart — why didn’t someone think about that a long time ago?”. This handy “end-cap” lets you quickly measure multiple new brass cases or deprimed FL-sized cases so you can get an average H20 capacity. The primer pocket plugs are NOT case-specific (they feature an O-ring that fits the pocket). One version will work with all small-primer-pocket cases, while another works with all large-primer-pocket cartridge types. Price is $19.95 for either small-pocket or large-pocket version.
NOTE: If you want to measure H20 capacity on fired, sized brass, but don’t want to shell out the money for the tool (or re-insert a spent primer), here’s a simple suggestion. When you size your case, first remove the decapping rod from the die. Then you can FL-size the case without removing the primer. Of course, you will eventually have to knock the primer out, and that requires putting the decapping rod back in the die and running the case through a second time. To avoid that hassle, the Primer Pocket Plug may be worth the $19.95 over the long haul. We just ordered one of each (small and large).
Product Find by EdLongrange. We welcome reader submissions.
21st Century Shooting crafts some of the best precision handloading tools you can buy. This company’s neck-turning tools, priming tools, funnels, flash-hole tools, and other specialty tools are truly excellent pieces of kit. The 21st Century neck-turner, fitted in the company’s innovative neck-turning lathe, is an outstanding system for turning case-necks. Now holiday shoppers can save money on 21st Century’s entire product line. 21st Century is offering 10% off all products ordered through its website, www.21stCenturyShooting.com.
To get 10% off your online order, simply use the Discount Code 1210holiday25 during check-out, placing “1210holiday25″ in the box marked “REDEEM CODE”. With the money you save you can buy more cool tools, or set aside your savings for bullets, brass, and powder.
Discount Tip from EdLongrange. We welcome reader submissions.
if you turn your case-necks, here’s a tool from 21st Century Shooting that can can save time, and help you produce better, more consistent turned necks. 21st Century’s Neck-Turning Lathe system, introduced last spring, may revolutionize the way reloaders turn their case necks. Watch the video and you’ll see why. If you’re never turned cases before, you may become a convert after seeing how quickly and easily the new 21st Century Neck-Turning Lathe does the job.
The mini-lathe has unique fittings on the left and right sides that allow both the case-holder and the neck-turning tool to float. As a result this tool maintains near-perfect concentricity during the cut. 21st Century’s John Perkins explains: “The floating design of the neck turner and the case driver allows the case mouth (bore) to run on the arbor absolutely concentric, therefore allowing O.D. to be turned concentric with I.D. The tailstock creates a horizontal inline support for the base of the case. This also allows the operator to keep both hands on the power screw driver or drill, making it very easy to control the feed rate and to produce a very fine, turned finish.” Having the system float at both ends was key, according to John: “By allowing both the turner and the case to float, everything self-aligns. This maintains concentricity and allows the unit to work with very low torque.”
Neck-Turning Lathe is Fast Yet Precise
Using power from a drill or electric screwdriver, this tool will turn necks fast — in a matter of a few seconds. And it produces beautiful, smooth necks that are extremely uniform. Tests show that the lathe, used with the 21st Century Neck-Turning Tool, will hold 0.0002 (two ten-thousandths) neck wall tolerances. And it will do that time after time.
Turn Necks in a Single Pass
Using traditional hand-methods, turning case necks can be time-consuming and fatiguing. Many folks will experience hand pain or cramping after just a dozen cases. Watch the video, you’ll see how fast and easy neck-turning can be with the new mini-lathe. You get an exceptionally good cut in seconds. Very importantly, with this system, you may be able to switch from a double-pass cut, to a single-pass cut. Yes, even if you’re making a deep cut, we think there is a good chance you can turn all your necks in a single pass. That can cut your labor time in half!
Why does the 21st Century Neck-Turning Tool cut so well? First, the Neck-Turning Tool employs ultra-sharp carbide cutters that are custom-ground to fit the shoulder angle of your cartridge. This allows you to make a perfect cut extending down the shoulder 1/32 of an inch. Second, the system aligns the case neck on the arbor (mandrel) so well, and the cutter is so sharp, that very little torque is required. This allows the cutting process to go very smoothly. The case-holder is also unique — it features a O-ring so it holds the case firmly in place without marring or bending the case head. The tailstock case-holder adjusts to accommodate cases from 17 Fireball to a .416 Rigby.
More Case Prep Tools for Lathe in Future
In the near future 21st Century will offer additional case prep attachments for the new mini-lathe. 21st Century plans to provide bullet-pointing system and other options. These will all work with the same lathe “chassis”, and will run with power. John states: “This is a modular system, all parts interchange. So if you have an existing 21st Century Shooting Neck Turning Tool or Bracket, everything will fit.”
The 21st Century Neck-Turning Lathe costs $245.00, complete with Neck-Turning Tool ($85.00 value) and one case-holder driver. The Neck-Turning Tool comes with a carbide cutter with user choice of shoulder angle (Arbors and Mandrels are sold separately). Perkins recommends using the Neck-Turning Lathe with power, but it will also work with an optional hand crank. NOTE: Currently the Neck-Turning Lathe works ONLY with the 21st Century Neck-Turner. It will not work with K&M, Sinclair, or Forster tools. But that’s not a real drawback because the 21st Century tool is certainly one of the best on the market today. You can purchase the Neck-Turning Lathe (complete with Neck-Turner and Case-Holder) through the 21st Century website, or call (260) 273-9909.
Disclosure: 21st Century Shooting advertises with AccurateShooter.com.
21st Century Shooting’s all-new Concentricity Gauge looks like a winner. The cartridge case rides on four spinning rollers that allow smooth turning movement with low drag. These rollers are far superior to a set of V-Block supports, or even some ball-type supports.
The amount of eccentricity (run-out) is measured with a high-quality horizontal dial test indicator. In this application, a horizontal indicator works better than the typical vertical dial indicator with spring-loaded shaft used in most other concentricity gauges. We think that, with 21st Century’s new Concentricity Gauge, you can measure cases faster, with less effort, and greater repeatability. In addition, this device can measure the INSIDE of the case neck, not just the OUTSIDE.
Overall, this is a very impressive new tool that is unquestionably superior to many other Concentricity Gauges on the market. Given the capabilities of this device, the price is reasonable: $169.00 including Horizontal Indicator. The Gauge by itself costs $125.00, while the Indicator alone sells for $59.00.
Click Photos below to view larger Images
Why the New 21st Century Concentricity Gauge Works So Well
21st Century explains the advantages of its new design: “At 21st Century Shooting, our goal to modernize an industry that has seen little change over the years. The new concentricity gauge is a perfect example. Most conventional concentricity gauges use what is called a height indicator gauge (Dial Indicator with vertical shaft). Although economical, this type of gauge was not intended for the purpose of measuring rotating diameters. The vertical-style indicator can produce inaccuracies due to indicator rod flex and bounce.
Our new Concentricity Gauge uses a horizontal dial test indicator. This type of gauge was designed specifically for checking rotating diameters and in fact is exactly the type of gauge used in the machining industry for decades to measure run out — the very thing that we as hand loaders are striving to minimize or eliminate.
Additionally, our new gauge uses Stainless Steel turning rollers as opposed to fixed bearings or V-block style case supports. You will especially appreciate the roller supports that glide on linear guide-ways. Plus, with a simple push of a button you can adjust the case support base width. No tools are needed to move the base on the built-in guide-ways.”
Product tip from EdLongrange. We welcome reader submissions.
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.
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.
The wizard tool designer who runs 21st Century Shooting has invented a clever yet inexpensive new bench accessory that makes it much easier to turn case-necks. 21st Century’s new Neck Turning Tool Swivel Bracket gives you a “third hand” when using the 21st Century Neck Turning Tool, simplifying the process of neck turning, particularly when using power.
CNC-machined from aluminum billet, 21st Century’s Swivel Bracket mounts right on your bench. You can either attach it semi-permanently with screws or simply clamp it in place. Adjust your neck-turning tool (red unit in photo), at any angle from 0-90°, for best viewing of the cutter operation. With your neck-turning tool attached to the bracket, you have easy access to the arbor adjustment screw, arbor screw clamp, and the bracket rotation clamp screw. Once you’ve adjusted the angle, and locked the neck turner in place with the supplied Allen wrench, you can concentrate on turning the case, either by hand, or with power assist. The neck-turning tool is held securely; however, rubber bushings on the bracket allow the neck-turning tool to “float” just enough to work properly when using power.
This new Neck Turning Tool Swivel Bracket is simple, but very effective. It really does help you turn necks with greater ease and a greater sense of security. Importantly, the bracket lessens hand fatigue. No more “cramped hand syndrome” from struggling to hold the neck-turner steady. We really like this little device, and it only costs $19.95. However, for the time being, the Swivel Bracket ONLY works with the 21st Century Neck Turning Tool — it does NOT work with a Hornady, K&M, Neilson, or Sinclair Neck Turning Tools. For more info, call 260-273-9909 or visit 21stCenturyShooting.com.
An arbor press’ basic function is simple enough: exert sufficient downward pressure on the die to either size the case neck or seat the bullet depending on which die is in use. It isn’t a mechanically challenging function. So why do we use an arbor press and what should be look for in one? Consistent operation, sensitive feel, quality of design and machining are the hallmarks of a good arbor press and this one from 21st Century comes away with good marks in all areas.
High Quality Machining and Parts Finishing
Editors’ Note: The designer of the 21st Century Arbor Press has decades of tool-making experience, and he has designed tools for many “big-name” companies. 21st Century stands behind the product with a lifetime warranty for the original purchaser. The Arbor Press is currently offered in four different versions, with two post heights (8.5″ or 10.5″), and two baseplate sizes (small 3″ x 4″ or large 4″ x 5″). Prices start at $94.99 for the 8.5″ post and small baseplate. 
Turn Necks in a Single Pass
Why does the 21st Century Neck-Turning Tool cut so well? First, the Neck-Turning Tool employs ultra-sharp carbide cutters that are custom-ground to fit the shoulder angle of your cartridge. This allows you to make a perfect cut extending down the shoulder 1/32 of an inch. Second, the system aligns the case neck on the arbor (mandrel) so well, and the cutter is so sharp, that very little torque is required. This allows the cutting process to go very smoothly. The case-holder is also unique — it features a O-ring so it holds the case firmly in place without marring or bending the case head. The tailstock case-holder adjusts to accommodate cases from 17 Fireball to a .416 Rigby.
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?”
