Another massive, data-driven field test has been completed by our friend, Cal Zant, over at PrecisionRifleBlog.com. The past few months, Cal has tested 20+ muzzle brakes designed for 6mm, 6.5mm, and .30-caliber precision rifles. Hundreds of hours have gone into this research, and it provides a lot of new insight and empirical data for several aspects of muzzle devices. Cal put a huge amount of labor/engineering into these tests and his findings deserve to be widely read.
Cal created a system to directly measure the entire recoil force signature of each muzzle brake using high-speed sensors. Although the recoil cycle happens very quickly (around 1/100th of a second), his test equipment could record up to 1,000 force data points during a single recoil cycle! He fired over 1,000 rounds of match-grade ammo through four different rifles: 6XC, 6.5 Creedmoor, .308 Win, and the monster .300 Norma Magnum. He literally spent thousands of dollars on this part of the test, to ensure he got it right.
Cartridge Types Tested: 6XC, 6.5 Creedmoor, .308 Win, and .300 Norma Magnum
Ability To Stay On Target
David Tubb helped Cal develop this part of the test, because David believes this is the most important aspect of a muzzle brake. Using a laser and high-speed camera, Cal was able to objectively quantify how well each design helped you stay on target.
Muzzle brakes are loud, but some are louder than others … three to four times as loud. Cal enlisted the help of an expert from the suppressor industry to precisely measure how much louder each muzzle brake made a rifle. Each brake was tested in accordance with MIL-STD-1474D using calibrated military-approved equipment, and the noise level was also tested at the shooter’s position. This produced some interesting results.
Zant also includes high-res photos of each brake, and plans to publish other info about each model (including price, whether it requires gunsmithing, what calibers it is available in, etc.) to make it easy to compare them side-by-side.
Cal recently started publishing the results of these tests, and there is already a lot of interesting info. The data might surprise a few people and even dispel a few myths. Particularly interesting is Zant’s comparison of recoil reduction with a suppressor compared to muzzle brakes. How do you think the suppressor performed compared to the brakes? You may be surprised.
We know our readers are curious about the new Tipped MatchKings (TMKs) introduced by Sierra Bullets this year. Our friend Bill at Rifleshooter.com got hold of some of the .30-Cal 175-grain TMKs and tested them in his .308 Win rifle. He found the bullets were very consistent in weight. As for bearing surface, the SD was fairly low (.002″), but measurements varied from 0.400″ to 0.407″. Seven-thousandths extreme spread is more than we like to see, as it may affect accuracy. Therefore we recommend you sort by bearing surface length before loading these in match rounds.
If you shoot an AR-platform rifle, you could probably use one of these gadgets. A brass-catcher keeps your brass in good shape and saves you the hassle of picking up fired cases. Moreover, nearby shooters no longer have to fear being pelted with your hot brass.
Varminter.com recently released a First Hunt Report on the new Savage A17 rifle. Savage’s new semi-auto .17 HMR has caused quite a stir. Accurate and affordable, the Savage A17 is also the first .17 HMR to feature a delayed blow-back action. We think the A17 may be the most important new rimfire rifle of 2015, so we were pleased to see that Eric Mayer, Editor of Varminter.com, put the new semi-auto Savage through its paces.
Mayer wanted to see how the new Savage would perform, accuracy-wise, and he also wanted to see how the A17 fared in the field. Mayer achieved one-MOA accuracy with the Savage A17 using the latest CCI-brand ammo, and he demonstrated the A17 is wickedly effective on ground squirrels. Here are some highlights from Varminter.com’s Savage A17 First Hunt Report:
Forum member Jacob spotted this simple, but effective set of scope ring inserts on the Brownells’ Website. With these inserts, you can use a scope with 1″-diameter body in 30mm rings. Non-marring, matte black Delrin sleeves surround the scope tube so it can fit larger-diameter rings. Each sleeve comes in two parts for easy installation around your scope tube. Ring Reducers are sold as front/rear kits. Cost is $14.99 for the 30mm to 1″ ring adapters, item 084-000-091.
Note: These Brownells units simply function as plastic bushings. Unlike Burris Signature Ring inserts, they do not allow you to “pre-load” windage or elevation. If your rings are misaligned, the Brownells Ring Reducers won’t correct that problem.
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AccurateShooter.com has released the most complete discussion of the 6.5×47 Lapua cartridge ever published. Our new 6.5×47 Cartridge Guide is packed with information. If you own a 6.5×47 rifle, or are thinking of building a rifle with this chambering, definitely read this Cartridge Guide from start to finish. Our comprehensive, 5000-word article was researched and written by the 6.5 Guys, Ed Mobley and Steve Lawrence. Both Ed and Steve shoot the 6.5×47 Lapua in competition and they are experts on this accurate and efficient mid-sized cartridge.
You’ll find everything you need to know about the 6.5×47 Lapua in our new Cartridge Guide. We cover ballistics, reloading, die selection, and we provide an extensive list of recommended loads, for bullets from 120 to 140 grains. You can read interviews with respected experts who’ve built and tested many 6.5×47 rifles. The Guide includes helpful tech tips such as how to maximize the powder fill in your cases. This Cartridge Guide can put you on the “fast track” — helping you develop accurate, reliable loads with minimal development time.
6.5×47 Lapua Cartridge Guide Highlights:
Comprehensive Load Data
Best Bullets and Primers for 6.5×47
Ballistics Comparison Charts
Sizing and Seating Die Options
6mm-6.5×47 (Necked-Down) Options
Ask the Experts Section
Tips for Accurate Reloading
Brass Life and Annealing
Chambering and Gunsmithing Tips
6.5×47 Lapua for Hunting
6.5×47 Lapua for Tactical Competition
6.5×47 Factory-Loaded Ammo
Here is a sample from the 6.5×47 Cartridge Guide’s Ask the Experts Section. This is an interview with Rich Emmons, one of the founders of the Precision Rifle Series:
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The 17 Winchester Super Magnum Rimfire (aka Win Super Mag or WSM) is the fastest, most potent modern rimfire round you can buy. This cartridge, which uses a modified nail gun casing, drives 20gr bullets at 3000 fps. The 17 WSM offers superior ballistics to all .22 rimfires, and is a clear step ahead of the 17 HMR. That makes this round a potential “game-changer” in the varmint fields. To guage the capabilities of the 17 WSM, Varminter.com tested the cartridge in the new Ruger 77/17 bolt-action rifle. Click HERE for Varminter.com Ruger 77/17, 17 WSM Review.
17 WSM shoots faster than the 17 HMR, so the 20gr bullets don’t drift as much in the wind:
Varminter.com reports: “The much-anticipated Ruger 77/17 chambered in the 17 Winchester Super Magnum (17WSM) has been released. Our Review Editor, William Chambers, put it through a full range test with all four currently-available ammunition loads. Afterwards, he took it on a short groundhog hunt[.] We put a lot of rounds through the guns we test, at targets, through chronographs and out in the field. This report includes all currently available 17 WSM ammunition and a sneak peek of the really nice Nikon Prostaff 5 riflescope.” READ REVIEW.
Retired engineer Alexander Müller (aka Nando-AS on our Forum) produces handsome oak ammo caddies in his home workshop. Cartridge-specific, the caddy’s holes are sized for specific casehead diameters, so your cartridges go in and out easily. There are also through-holes, allowing loaded cartridges to be placed nose-down if you wish.
Any experienced varmint hunter knows the value of a good .17 HMR rifle, particular when used inside 150 yards on small critters such as ground squirrels. The .17 HMR is a great round, but for general plinking and target practice, we prefer shooting the venerable .22 Long Rifle. The .22 LR has less recoil and less noise. Importantly, .22 LR ammo (even with today’s shortages) remains much less expensive than .17 HMR ammunition.
Wouldn’t it be great if a single, affordable varmint rifle could shoot both .22 LR and .17 HMR? Well, CZ offers just such a rig — the CZ Model 455 American Combo, a versatile switch-caliber rifle priced at about $485.00 (MSRP is $531.00). The American Combo comes complete with both .22 LR and .17 HMR barrels, easily interchanged with a simple Allen wrench. As CZ explains: “The CZ 455 eliminates the need to spend the extra expense on a second rifle when you want to add another quality shooter to your rimfire battery”. For a bit more money, you can even purchase a .22 WMR barrel, making your CZ a triple-threat varmint-slayer.
Father’s Day is June 21, 2015, less than a week away. If your father enjoys the shooting sports, here are some recommended items that every shooter can use. All selections cost less than $100.00. It’s not too late to order. If you have an Amazon Prime membership, you can get two-day shipping in most areas of the country. For non-Prime members, most items will ship in 3-4 days. That’s enough time to get the gift to “Pops” by next Sunday.
The light-weight, compact RCBS Partner Press is ideal for loading at the range. It can easily be mounted to a bench with C-Clamps.
This Editor has a MidwayUSA injection-molded gun cradle, now sold as the Tipton Gun Vise. This product has worked well for everything from an 18″-barreled lever gun to a 32″-barreled F-Class rifle. The unit has proven invaluable for many tasks: cleaning barrels, stock refinishing/bedding, scope mounting, trigger adjusting, bore-scoping barrels, and checking throat length with a Hornady OAL tool. To be honest, I can’t understand how any serious shooter can get along without a product such as this (MTM makes a similar plastic cleaning cradle). That said, The unit isn’t perfect. This gun vise will NOT fit rifles with forearms wider than 3 inches. And if your butt-stock is very shallow (vertically) from comb down to toe, it may not fit the clamping system very well. But, for 95% of the rifles out there, the Tipton Gun Vise works great.
Bargain Pricing on Amazon.com
The Tipton Gun Vise is on sale on Amazon.com for $39.89.
That’s a very good deal for a product you’ll use for years.
Bullets.com has released a new, advanced handle-actuated primer seating device. Bullets.com President Shiraz Balolia tells us: “We have designed a new bench-mounted Bald Eagle Primer Press. It seats primers very consistently and you can adjust the depth of the primer in .002″ increments. I have been using one for months. In fact, I used it for the Canada win and also during the Nationals last year where our Team won the National Championships.”
Tactical ace Zak Smith of Thunder Beast Arms employs a simple, handy means to store his elevation and wind dift data — a laminated data card. To make one, first generate a come-up table, using one of the free online ballistics programs such as JBM Ballistics. You can also put the information in an Excel spreadsheet or MS Word table and print it out. You want to keep it pretty small.
Above is a sample of a data card. For each distance, the card includes drop in inches, drop in MOA, drop in mils. It also shows drift for a 10-mph cross wind, expressed three ways–inches, MOA, and mils. Zak explained that “to save space… I printed data every 50 yards. For an actual data-card, I recommend printing data every 20 or 25 yards.” But Zak also advised that you’ll want to customize the card format to keep things simple: “The sample card has multiple sets of data to be more universal. But if you make your own data card, you can reduce the chance of a mistake by keeping it simple. Because I use scopes with MILS, my own card (photo below left) just has three items: range, wind, drop in MILS only.”
In our Shooters’ Forum, one member recently asked: “What makes an AR accurate? What parts on an AR can really affect accuracy — such as free-floating handguards, barrels, bolts, bolt carriers?” He wanted an honest, well-informed answer, not just sales pitches. Robert Whitley posted a very comprehensive answer to this question, based on his experience building and testing dozens of AR-platform rifles. Robert runs AR-X Enterprises, which produces match-grade uppers for High Power competitors, tactical shooters, and varminters.
Building an Accurate AR — What is Most Important
by Robert Whitley
There are a lot of things that can be done to an AR to enhance consistent accuracy, and I use the words “consistent accuracy” because consistency is a part of it (i.e. plenty of guns will give a couple great 5-shot groups, but won’t do a very good 10- or 20-shot groups, and some guns will shoot great one day and not so good on others).
Here are 14 key things we think are important to accuracy.
1. Great Barrel: You’ll want a premium match-grade barrel, well-machined with a good crown and a match-type chambering, true to the bore and well cut. The extension threads must also be cut true to the bore, with everything true and in proper alignment.
2. Rigid Upper: A rigid, heavy-walled upper receiver aids accuracy. The typical AR upper receiver was made for a lightweight carry rifle and they stripped all the metal they could off it to make it light to carry (which is advantageous for the military). The net result are upper receivers that are so thin you can flex them with your bare hands. These flexible uppers are “strong enough” for general use, but they are not ideal for accuracy. Accuracy improves with a more rigid upper receiver.
Here’s something you’ve never seen before, a joy-stick (coaxial) bipod with a front counter-weight. This one-of-a-kind “JoyPod” was produced by Seb Lambang for our friend Darrell Buell. With a very porky ultra-long-range rifle to support, Darrell needed a JoyPod that wouldn’t sink under a heavy load.
Seb explains: “This is the world’s first Joypod equipped w/ an adjustable counterweight, to balance his 75-lb gun. I did some experiments and put some weights ranging up to 60+ lbs on the top, and I found that the joystick action works like a regular one….it’s smooth, light, and precise. In addition, the counterweight can be bent down to not interfere with the bottom of the barrel. I would guess Darrell would only need one ‘ring’ for his 75-lb gun. He can move the ring back and forth to find the best balance. Once the gun is on the bipod, it would only take a few minutes to tune or find the balance. The counterweight is secured into the front center shaft by a thumb screw, and there is a tightly fitted pivotal joint on the counterweight to allow angle adjustment.”
With the end summer, the shooting season in full swing. When you head to the range you’ll want to be prepared. That means collecting all the gear you’ll need at the range. It’s easy to forget small, critical items, so we’ve provided a checklist of the small “extras” you should pack before you head out to the range. In addition to rifle, rests, ammo, targets, and cleaning gear, here are a dozen essentials you should include in your range bag.
• Shell-Holder — If you don’t have calipers, you can use a shell-holder to check for excessive case expansion from hot loads. If a fired case doesn’t slip into the shell-holder easily, your load is definitely TOO HOT.
• Extra Earplugs — Always use ear protection when shooting. We bring a 35mm film canister with extra sets of foam earplugs.
• Hex Wrench or Screwdriver for action screws — Action screws can work loose with time. Always bring the appropriate hex wrench or screwdriver whenever you go to the range.
• Small Wrench for Scope Rings — Check the tension of your scope base and ring fasteners before you go. Bring along a small Torx wrench for the ring screws (or other tool that fits your fasteners).
This is an interesting technical article prepared by Action Target, a leading steel target manufacturer based in Provo, Utah. With technical data provided by the American Iron and Steel Institute in Washington D.C., this report is designed to cut through the recent hype and establish a basis of fact for accurate evaluation and comparison.
What Is Steel?
Steel is an alloy metal composed of iron and varying amounts of carbon and/or other elements such as chromium, nickel, tungsten, manganese, and so on. Steel with specific properties and characteristics is created by adjusting the overall chemical composition or by altering the various production processes such as rolling, finishing, and heat treatment. Because each of these factors can be modified, there is potentially no limit to the number of different steel recipes that can be created. Currently, there are over 3,000 cataloged grades or chemical compositions of steel available. Steel can utilize a wide variety of alloying elements and heat treatments to develop the most desirable combination of properties.
This is one amazing .50-caliber rifle. Along with the lever-actuated falling block, it has a massive swing-out breech block like you’d find on a field artillery piece. The action is so wide that the sights and scope are offset. You’ve heard of the “Beauty and the Beast”? Well here the Beast IS a Beauty….
View looking down at the action from above. Note the hinged Breech-Block.
AccurateShooter.com Forum members often ask: “Is there a reasonably-priced ammo box that fits PPC and BR cases just right?” The answer is yes — check out the 50-round Frankford Arsenal model 512 ammo box. It is offered in transparent blue or smoke gray for $3.49 per box at MidwayUSA (or $3.99 per box at Amazon.com).
The cartridge slots are just the right size for 22BR, 6mmBR, 30BR, 220 Russian, 6 PPC, 6.8 Rem SPC, 6.5 Grendel, and 7.62×39 cartridge cases. Cells are 1.687″ high x 0.392″ square, with a divider height of 0.94″. That will hold BR-type cases securely, and fired brass won’t get jumbled if you tip-over the box.
The $52.99 RCBS Precision MIC is a well-made and useful tool for measuring cartridge headspace and bullet seating depth. The Precision Mic measures from a datum point on the case shoulder to the base. Unfortunately the Precision MIC is not specifically made for the 6mmBR Norma, 22BR, 6XC or 6.5×47 Lapua cases. Don’t despair. Reader Caduceus devised a clever way to adapt a .308 Win Precision Mic for short cases that match the .308 Win in rim diameter and case body diameter. He simply creates a spacer out of a pistol cartridge. He trimmed a 9mm case to 0.511″ and “found this to be a perfect fit which gave a zero micrometer reading when the FL-sized 6BR case was placed in it.” We expect many readers already own a Precision Mic for their .308s. Now you can adapt this tool for the 6BR family of cartridges, for no extra cost. Cut the spacer shorter for the 6.5×47 Lapua and 6-6.5×47 cartridges.
How to Use the Precision Mic with a Spacer
Caduceus explains: “I can use the .308 version of the RCBS Precision Mic to compare brass which has been fully sized in my 6BR body die with brass which has been fired in my chamber. With the spacer inserted, FL-resized cases mic 0.000″ at the datum point on the shoulder. Using the same set-up, fire-formed cases measure +0.005″. In other words, my chamber has a headspace of +0.005″ above minimum dimensions. This is fairly typical of a custom rifle set up for switch-barrel use. If I were to FL-resize my brass down to minimum spec each time, this excessive working would shorten its life-cycle and might lead to case head separation. Now that I know the headspace of the chamber, I can substitute the standard shell holder on my press with a Redding +0.004″ competition shell-holder. This ensures that my cases only receive 0.001″ of shoulder set-back.”
Click HERE for a full article explaining how to adapt an RCBS Precision Mic for use with a 6BR. You can do the same thing with a 6XC or 6.5×47 case–just cut the spacer to a shorter length (for an 0.000″ mic reading). Note: You can also use this procedure with an RCBS .243 Winchester Precision Mic.
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