July 25th, 2012

New Wheel-Drive Concentricity Gauge from Accuracy One

Talented tool-maker Curt Knitt has designed a better mousetrap — a new Concentricity Gauge that makes it easier than ever to get fast, repeatable results when measuring case and bullet run-out (aka “eccentricity”). The breakthrough design feature is the large-diameter wheel which spins the case. With most other concentricity gauges you must rotate the case with your finger(s). Anyone who has tried this knows that it is difficult to get a full, 360° rotation of the case without disturbing the indicator. Typically you can get two-thirds of a rotation or so, but then you have to reposition your finger to complete the rotation. Moving your finger often causes the case to jiggle or move slightly, and more often than not, the dial indicator jumps a bit, interrupting your measurement. Been there, done that.

Accuracy One Concentricity Gauge

Drive Wheel Smoothly Spins Cases for Fast, Error-Free Readouts
With the new Accuracy One Concentricity Gauge from CTK Precision, the rubber-rimmed drive wheel has a much larger diameter than any cartridge case (7:1 diameter ratio on magnums). So, when you rotate the drive wheel just a half-turn or so (using knurled knob on the wheel axis), you can easily and smoothly turn the cartridge three (or more) full rotations. The drive wheel maintains a constant, even load on the case, so the case doesn’t wobble and the dial indicator gives a continuous, un-interrupted read-out. What’s more, clever cartridge support design geometry pulls the case back against the rim stop as you engage the drive wheel. This holds the case in position laterally during measurement. Morever, this allows very fast one-handed operation. You don’t have to hold the case down with your fingers while maintaining side force against the case rim stop.

Watch Video Showing Concentricity Gauge Used with Small and Large Cartridges

Accuracy One Concentricity GaugeThe Accuracy One Concentricity Gauge works with the full range of cartridges — everything from .22LR to .50 BMG. Adjusting the tool for different-length cases is incredibly easy, because the roller blocks (case supports) are held in place by magnets. You just slide the blocks to the desired position — no tools needed! The indicator stand is also held by magnets so it can slide to any position you want along the case body or bullet. And, the indicator can be moved to the front rail and rotated 90°. This way you can measure on the inside of the case neck.

Does this new design really work? Absolutely — it works brilliantly and it’s FAST. Watch the video and see for yourself. We could do two-rotation (720°) measurements on cases in a third the time it takes to do a one-rotation gauging operation with other tools. And the actual measuring operation can be done one-handed, leaving your free hand to pic up the next case (or bullet) to be measured. And yes, this tool can also measure bullet concentricity — measured from tip, ogive, bearing surface, and/or boatail.

Accuracy One Concentricity Gauge

1. Directional Drive Wheel pushes the cartridge or bullet into the stop for accurate, repeatable readings with equal pressure. The replaceable rubber drive ring will not harm cartridges or bullets.

2. Two-position bullet and cartridge stop.

3. Precision ball bearings provide friction-free movement.

4. Heavy steel base with E-coat finish and bolt-on rubber feet.

5. Indicator stand and roller blocks ride in machined slots and are held in place by N42 Neodymium magnets. This allows rapid, smooth, tool-free adjustments.

6. Indicator stand can be place in front OR rear machined slots. This allows for both internal and external measurements.

7. Fine-Adjustment Horizontal Indicator Stand allows very precise indicator angle/load adjustments.

8. Indicator Stand will accept horizontal indicators that are .350″ wide or narrower, and are 1.75″ to 2.25″ from the indicator contact point to the center of the main body.

9. Adjustable mechanical arm stop holds the arm up for one-handed operation.

10. Precision Drive Wheel has a 13:1 ratio for .22 rimfire, 7:1 for magnums, and 3.7:1 for 50BMG.

11. Concentricity Gauge accepts cartridges from .22LR rimfire to .50 BMG.

The Accuracy One Concentricity Gauge is available from BulletTipping.com. Price for the unit, complete with quality horizontal indicator, is $325.00. Price, without indicator, is $280.00. The initial run of Concentricity Gauges is now in final production. Gauge sets should hit the market in 4 to 6 weeks. To place an advance order, fill out the PDF Order Form, or call (814) 684-5322. To learn more about setting up and using this new tool, read the Concentricity Gauge Instructions, and watch the video above.

Permalink Gear Review, New Product, Reloading 9 Comments »
July 25th, 2012

Varminters Need One-Rev Elevation Knobs Too

Hey Burris, Leupold, Sightron and Weaver — are you reading this? If you want to dominate the market for varmint scopes, give us a large elevation knob offering at least 20 MOA in a single revolution. IOR and U.S. Optics already offer this “one-rev” option on tactical scopes and it is clearly superior when moving back and forth between multiple yardages. Schmidt & Bender offers a single-turn option on some S&B PMII Tactical scopes, along with a color-coded, double-turn elevation turret option.

IOR Scope Elevation

IOR’s big 9-36×56 scope offers 25 MOA of elevation in ONE ROTATION (and about 75 MOA overall). If you use the zero stop, that one rotation (25 MOA) will get most rifles to 850 yards with ease (and very few varmint shots are made beyond that). That means you should never loose track of your elevation setting. Right in front of your nose is a large visible number that corresponds to your actual come-up: “7” for 7 moa, “12” for 12 moa, and so on. Wow–this is so easy compared to other systems that require multiple revolutions and leave you staring at unlabeled hash marks wondering how many clicks you just dialed in or out.

IOR Scope Elevation

When this Editor first tried a one-rotation elevation knob I had the same reaction I did years ago when I watched a ultra-high-grade flat screen TV for the first time. Then I thought… “wow, this flat screen is just better in every respect and, eventually, will change everything.” Scopes aren’t TV sets, but I think the large one-rotation knob IS a huge advancement — a breakthrough in scope design. When used with a come-up table showing the elevation needed for various yardages (50-1000 yards), the one-rev system makes it really hard to be “way off” in your elevation. With conventional elevation knobs it is very easy to lose track of clicks (and whole revolutions) as you move up and down to different yardages.

USO Scope ElevationThe IOR and U.S. Optics products offering 20+ MOA in one-revolution are large, heavy, expensive scopes. The big elevation knob on the IOR Ultra Long Range scope has about 125 MOA total elevation (25 MOA per turn) with 1/4-MOA clicks. The large flat EREK (Erector Repositioning Elevation Knob) on the U.S. Optics scopes offers 22.5 MOA per revolution, with a total of about 62 MOA in a 5-25 SN-3 model with 1/4-MOA clicks.

Scope-Makers Should Adapt Technology to Varmint Scopes
It’s time for the mainstream scope makers to bring this techology to the market. Adding a one-revolution elevation knob (with 25 moa of travel) to a $600.00 varmint scope would make a huge difference in practical functionality in the field. You could reliably click back and forth between yardages all day long and never lose track of your elevation setting. This is almost as easy as a yardage-calibrated elevation knob (but not limited to a single load.) So, you scope makers out there… How about giving us a one-revolution elevation knob on an affordable hunting scope?

U.S. Optics EREK photo © 2005 Precision Rifle & Vince Bottomley, used with permission.

Permalink Gear Review, Optics 8 Comments »