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June 14th, 2015
Find Optimal Barrel Twist-Rate with Berger Stability Calculator
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June 7th, 2015
Beat the Heat with Barrel Temp Strips
You never want your barrel to get too hot. Accuracy suffers when barrels over-heat, and excessive heat is not good for barrel life. So how do you monitor your barrel’s temperature? You can check if the barrel is “warm to the touch” — but that method is not particularly precise. There is a better way — using temperature-sensitive strips. McMaster.com (a large industrial supply house) offers stick-on temp strips with values from 86° F to 140° F. A pack of ten (10) of these strips (item 59535K13) costs $10.71. So figure it’ll cost you about a buck per barrel for strips. That’s cheap insurance for your precious barrels.
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June 4th, 2015
.308 Win Barrel Cut-Down Test: Velocity vs. Barrel Length
With barrels, one wonders “Can a little more length provide a meaningful velocity gain?” To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length.
Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering)
Summary of Findings: The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. By ammo type, the average loss per inch was: 24.6 (Win 147 FMJ), 22.8 (IMI 150 FMJ), 20.9 (Fed GMM 168gr), and 22.5 (Win 180PP). Interestingly, these numbers jive pretty well with estimates found in reloading manuals. The testers observed: “The Berger Reloading manual says for the 308 Winchester, ‘muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24″ barrel’.” How the Test Was Done
CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. All in all, this was a very thorough test by the folks at RifleShooter.com.
April 25th, 2015
Yank Barrel-Maker Helps Lady Win NZ Vintage Rifle Title
You have to love it when a prototype product not only performs well, but actually wins a match. For some time, Criterion Barrels has been working on a match-grade barrel for vintage Lee-Enfield rifles. It looks like they got things right… Over the Easter weekend the New Zealand Service Rifle Association held its annual national service rifle competition. Coming first in the Classic Bolt Action class was Wellington’s Nicole McKee shooting a Lee-Enfield with a new, prototype Criterion barrel. Nicole’s rifle was built by her husband Duncan, a vintage rifle expert who specializes in accurizing the No. 4 and SMLE actions. Nicole’s .303 British handloads featured Hornady 174gr FMJ Boattail bullets (SKU: 3131) pushed by 47.0 grains of ADI 2209 (H4350). ADI 2209 has become the top go-to powder for .303 British shooters in New Zealand. (more…)
April 4th, 2015
Muzzle Threading — Don’t Remove Too Much SteelOur friend Robert Whitley of ARX Enterprises LLC has learned, through careful measurement and testing, that some barrels threaded 5/8″ x 24 tpi at the muzzle may not deliver optimal accuracy. The reason is that the end of the barrel can bell out slightly, like a trombone, because too much steel has been removed. This is particularly true with .30-caliber barrels, but it can also be a problem with smaller caliber barrels (even 6mm). Robert demonstrates this phenomenon in the video below. All gunsmiths, and anyone considering threading a barrel, should watch the video. At 1:00 – 1:30 Robert gauges a 5/8″ x 24-threaded .30-Caliber barrel. You can see the belling effect clear as day.
Solve Problem with a Larger Thread Diameter
“See how much meatier the 3/4″ threading is vs. the 5/8″. The 3/4″ threading offers a lot more metal around the bore. There’s a lot less opportunity for the bore to become bell-mouthed…” – Robert Whitley Barrel Threading Diameter — What’s Important to Know I don’t think there is any better and realistic option than the 3/4” muzzle threading, and we also do it so there is no relief cut behind the threads on the barrel (i.e. put the relief cut on the brake or jam nut, don’t chop down on the muzzle of the barrel). For some reason many have a hard time grasping that the metal at the muzzle end of a rifle is “sacred” and you should not cut it down any more than absolutely necessary. A little threaded pencil diameter nub on the end of a barrel is not ideal for accuracy especially if it’s threaded and you need to torque on it. I cringe when I see a barrel with something like an MTU or Heavy Varmint contour, only to have an itty-bitty pencil thin threaded nub right at the muzzle so someone can “screw on a can” or a muzzle brake. Lessons Learned Over the Years What he did was rough contour the barrel with the turndown (about .010” oversize) before he lapped the barrel, then when he lapped the barrel he took it easy in the muzzle area and worked the back of the barrel more. I thought he was a little bit excessive in his concerns but the barrel shot great and I wasn’t going to argue with him, after all he was shooting groups in the ones. I kind of just filed that away and never thought about it until recently when I went to have Fred from Sabreco do some chamber re-work on a commercial .30-caliber barrel I had. When setting up the barrel in the lathe and indicating things Fred noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015” smaller [than what would fit] at the muzzle and he mentioned it to me. That precipitated my pin- gauging of a number of different commercial barrels I had that were threaded for 5/8” x 24 tpi. What I found is what’s shown on the video. NOTE: This is a copyrighted article. Do not reproduce or re-link more than 75 words without written permission from AccurateShooter.com.
April 1st, 2015
Gun Tech: Top Barrel-Makers Adopt Degaussing TechnologyAdvancements in barrel technology in recent decades have been impressive. Today’s premium barrels deliver accuracy that could only have been dreamed-of decades ago. And now a new development promises to help barrel-makers craft the most uniform, consistent, and stable barrels ever. What’s the new technology? You may be surprised. It’s not a surface treatment, or a cryogenic bath. The latest development in barrel manufacturing is Degaussing — the process of de-magnetizing metal objects. Degaussing is now used in many industries to uniform metallic products and to prevent unwanted interactions with magnetic fields. LEARN MORE. Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss. At the recent IWA show in Germany, Vallon GmbH, a German manufacturer of degaussing machines, told us that two major Wisconsin barrel-makers have purchased Vallon industrial degaussing units. The units sold to the American barrel-makers are similar to Vallon’s EMS unit show below. This can degauss (i.e. de-magnetize) 50 barrel blanks in one pass.
The Vallon degausser works by passing the barrel steel through a coil. Vallon explains: “The density of magnetic field lines is at its maximum in the coil centre, and is strongly decreasing towards the outside. If a ferromagnetic work piece (steel) is introduced into the coil, the field lines are concentrating and flooding the work piece. The conductivity of steel is up to 800 times higher than that of air. Degaussing is done during a continuous movement of the work piece, leading out of the coil. Decreasing field strength is achieved by a slow extraction from the coil.”
How Degaussing Improves Barrel Steel and Rifle Performance Here a barrel is checked after degaussing with a Vallon EMS. The meter records a zero magnetic value, showing complete degaussing success. Degaussing Will Add $50.00 to Barrel Cost
February 24th, 2015
Tech Trends: Precision Barrel Bore-HoningSome custom barrel makers are now honing barrels (after drilling) to improve bore diameter uniformity, smooth the interior finish, and reduce barrel lapping times. For years, large-scale manufacturers of hammer-forged barrels have employed honing. Now the process is being used by smaller, “boutique” barrel-makers. This article explains how and why barrel honing is done. Take the time to watch the video. For anyone with an interest in barrel-making, this video is an eye-opener… Barrel Honing Process Demonstrated (Worth Watching!):
A key manufacturing process used for hammer-forged barrels is now getting attention from the makers of custom button-rifled barrels. This process is precision bore-honing. Honing produces a high-quality bore surface fast, which is critical to hammer forging. (Why is honing so important with hammer forging? Surface finish is the one feature of the barrel that cannot be controlled in hammer forging. Surface imperfections in a barrel blank tend to be amplified as the blank is formed on the rifling mandrel. And if the bore is chromed afterwards, imperfections in the surface finish become even more obvious.) Honing dramatically improves bore diameter size uniformity and accuracy, surface finish and roundness throughout the length of the barrel. It can certainly be used in place of a pre-rifling lap. The chief difference between a lapped and honed bore is the direction of the finish lines in the bore. Honing leaves fine spiraling crosshatch lines, while a lap leaves lines going longitudinally in the bore. After rifling the manufacturer can remove the crosshatch finish with a quick lap if desired. Honing is fast, accurate, and can be automated. Its surface quality and geometry can duplicate lapping, except for the longitudinal lines of the lapped finish.
Computer-Controlled Bore-Honing
January 13th, 2015
Calculate Barrel Weight with FREE Software from Dan Lilja
For general info on barrel weight calculation for straight and straight tapers, read this article on Lilja’s website. Click HERE for another article explaining weight calculation with barrels that have a radiused (curved) contour section. Here are the free software programs offered by Dan Lilja. Right click and “Save As”: Straight Contour (.exe file) | Straight Contour (Excel file) | Contoured Barrels with Radius (Excel file)
December 30th, 2014
Life and Death of a Barrel — Can Barrel Useful Life Be Predicted?We can predict, with some certainty, how long a light bulb will last (in use), or a shingle roof, or even a nuclear reactor. But how about barrels? Is there a way to reliably estimate barrel life based on known characteristics? This article explains one effort to quantify barrel life…
Is there a more reliable way to predict barrel life — one that will work for a broad range of calibers? Well, Forum member MikeCr has developed an Excel spreadsheet that accounts for a number of variables, and gives a pretty good estimate of useful barrel life, whether you’re shooting a .223 Rem or a 338 Lapua Magnum. Mike’s program predicts barrel life using five variables: 1) Bullet Diameter; 2) Powder Charge weight; 3) Powder Heat Potential (KJ/kg); 4) Pressure (in psi); and 5) Bullet Coating (yes/no). Mike provides a table with Heat Potential ratings for most popular powder types. The user needs to know the pressure of his load. This can be estimated with QuickLOAD. You can download the lastest version of Mike’s spreadsheet below. You’ll need Excel or an Excel viewer to open the file. Click to Download Spreadsheet: Barrel Life Spreadsheet (Latest Version) Shown below is Mike’s Spreadsheet, with variables for a 6BR shooting 105gr “naked” bullets with 30.3 grains of Hodgdon Varget powder. The formula predicts 2401 rounds of barrel life. That corresponds pretty well to what we’d expect for a 6BR — about 2500 rounds.
Mike observes: “There has been a lot of discussion lately related to cartridge design and resulting barrel life. This is a really important factor to consider amongst a myriad of choices. Barrel life is controversial, and subjective. There are no clear-cut standards for comparison. But a few years ago, I put together a spreadsheet based on Bart Bobbit’s rule of thumb. It worked pretty good, only occasionally failing some tests when validated against posted barrel lives. According to Ken Howell, I had to account for pressure. And Henry Child’s powder temperature testing provided another piece needed. So, I’ve tweaked it here and there to pass more tests. From 223 Rem to 300 UltraMagnum. Another element added, but turned off, is shot interval. I would need way more tests to lock in on this. But everyone knows, the faster you shoot, the worse the barrel life. Anyway, another factor hard to define is ‘accurate’ barrel life. This cannot be quantified without standards. Barrels are replaced when expectations are no longer met. I feel that a [barrel] passes peak potential in a finite period due to throat erosion. But that don’t mean it’s toast, if it still shoots well enough. It’s just as likely that many of us never see that peak potential anyway. It’s a slippery thing. Point-blank BR competitors will toss a barrel when it leaves the 1s. I could get another 4000 rounds from it, and be content with its performance, I’m sure.” NOTE: Mike says: “This spreadsheet may show a lower barrel life than you prefer. But it pretty well spotlights cartridges to stay away from if you plan much time at the range or in dog town.”
December 25th, 2014
Candy-Cane Barrel for ChristmasWhat do you get when you combine red Cerakote and barrel fluting? Well, a candy-cane AR barrel — just in time for the holidays. This unique barrel was created by Black Hole Weaponry in St. Helens Oregon. No this is not a Photoshop job. This barrel is really finished this way (as you can see in the close-up). Thanks to Anette Wachter, aka 30 Cal Gal, for finding this festive firearm fitting.
December 15th, 2014
BoreSmith Patents Triangular Patches and Dual-Diameter BrushesThe U.S. Patent Office has awarded BoreSmith utility patents for two unique gun cleaning products. Patents were issued for BoreSmith’s triangular Pyramid Patch™ as well as BoreSmith’s dual-diameter JagBrush™. Both products were designed by Shane Smith, a mathematician/physicist who used his scientific and firearms knowledge to create innovative bore-cleaning products that may well work better than conventional patches and brushes. BoreSmith’s clever Triangle Patch™ (aka Pyramid Patch) presents more cleaning surface area to the bore wall than does a conventional square or round patch (of equivalent size). At the same time, the unique geometry makes Triangle Patches much less likely to jam in the barrel. This is because the notches in the sides of the triangle allow the patch to sit more uniformly on the jag (without bunching up). The Triangle patch can be used with a standard jag but works best when paired with BoreSmith’s patented dual-diameter JagBrush. Order Triangle Patches HERE.
Triangle Patch Function and Geometry Explained (See 1:18 time-mark): Patent Awarded to Dual-Diameter JagBrush
December 8th, 2014
McRee’s Pre-Fit Barrel Option for Rems and Rem Clones — $412.50Need a new barrel for your Remington-actioned hunting or tactical rifle? McRee’s Precision has you covered. McRee’s is now offering complete, no-gunsmithing re-barreling kits for Remington and Rem-clone actions. These feature a high-quality, pre-chambered “PRE-FIT” stainless barrel from Criterion, a Savage-style barrel nut, a recoil lug, and a special barrel-nut wrench. With this system you can easily re-barrel your favorite Remington rifle yourself in less than an hour. You don’t need to pay gunsmithing fees, or wait weeks (or months) for a busy smith to do the job. McRee’s Precision Remington DIY Barrel Kit includes Criterion Pre-Fit Stainless Barrel, Barrel Nut, Recoil Lug, and Barrel Nut Wrench: Right now McRee’s Precision is offering Rem-action Pre-Fit barrel packages (complete with barrel nut, recoil lug, and wrench) starting at just $412.50 (On Sale). Choose from four chamberings: .243 Win, .260 Rem, .308 Win, and .300 Win Mag. These Pre-Fit barrel kits are “100% complete and ready-to-install”. All you need to do is remove your current barrel, place the recoil lug, spin on the new tube, follow the instructions for setting head-space, then torque the barrel nut against the lug. NOTE: You may require a barrel vise and action wrench to remove the original barrel. Minor inletting changes may be needed forward of the action.
Product Tip from Ed LongRange. We welcome readers’ submissions. 
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Ask a Sailor — F-Class Champion and
Are you re-barreling a match rifle and need to know if you will still make weight? Or perhaps you want to select the right contour to hit an optimal carry weight for a new varmint rifle? Dan Lilja offers 
How long will a barrel last before the accuracy “goes south”? There are so many variables involved (powder type, bore diameter, bullet coatings etc.) that it’s hard to predict. You might say “Well, my buddy has a .243 and he got 1500 rounds before the throat was shot out” — those kind of comparisons can be useful, but they’re not very scientific, and they won’t help much if you’ve got a gun in a new chambering (such as the 6.5×47) for which long-term test results are lacking.
