Craters may look interesting on the moon, but you don’t want to see them on your primers. Certain mechanical issues that cause primer craters can also cause primer piercing — a serious safety problem that needs to be addressed. If you have a gun that is cratering primers (even at moderate pressure levels), there is a solution that works with many rifles — send your bolt to Greg Tannel to have the firing pin hole bushed.
Shooters who convert factory actions to run 6BRs, 6PPCs or other high-pressure cartridges should consider having the firing pin bushed. These modern cartridges like to run at high pressures. When running stout loads, you can get cratering caused by primer flow around the firing pin hole in the bolt face. The reason is a little complicated, but basically the larger the hole, the less hydraulic pressure is required to crater the primer.
A limited amount of cratering is normally not a big issue, but you can reduce the problem significantly by having a smith fit a bushing in the firing pin hole. In addition to reduced cratering, bushing the firing pin often produces more consistent ignition.
This is a highly recommended procedure that our editors have had done to their own rifles. Greg Tannel (Gre-Tan Rifles) is an expert at this procedure, and he does excellent work on a wide variety of bolts. Current price for a bushing job, which includes turning the firing pin to .062″, is $92.00, or $100.00 with USPS Priority Mail return shipping.
If you have a factory rifle, a bushed firing pin is the way to go if you are shooting the high-pressure cartridges such as 6PPC, 6BR, 6-6.5×47 and 6.5×47. This is one of the most cost-effective and beneficial upgrades you can do to your factory rifle. For more info on the Firing Pin Bushing process, visit GreTanRifles.com, or email greg [at] gretanrifles.com. After clicking the link for GreTanRifles.com, Click on “Services” > “Shop Services” and you’ll see a listing for “Bush Firing Pin Hole & Turn Pin”. CLICK that Box.
Firing Pin Hole Bushing by Greg Tannel
Work Done: Bush firing pin hole and turn pin
Functions: Fixes your cratering and piercing problems
Price: $92.00 + $8.00 return shipping Total Price: $100.00
Actions for which Bushing is Offered: Remington, Winchester, Savage multi-piece pin, Sako, Kimber, Nesika, Stiller, BAT Machine, Kelbly, Lawton, Surgeon, Borden, Wichita, Hall, Ruger, Howa, Weatherby, Dakota, Pacific Tool, Phoenix, and Defiant bolt action rifle or pistol.
Actions for which Bushing is NOT Available: Case hardened receivers, ARs, Accuracy International (AI), Barnard, Big Horn, Cooper, Desert Tactical Arms, Kimber, Rosenthal, New Savage single piece pin, Rim fires, Falling block, Break open, Lever, Pump rifles, 1903-A3, CZ, Mauser.
How to send your bolt in to be bushed:
Send your bolt and firing pin assembly via snail mail, priority mail, or UPS. Please do not use FEDEX as it sometimes has delivery delays.Include your name, phone number, and return shipping address, and a note as to what you want done. Pack your bolt carefully and ship to: Gre’-Tan Rifles, 24005 Hwy. 13, Rifle CO 81650.
Due to the high volume of work, turn-around time for bolt bushing jobs can be 12 weeks (though it usually is faster). Customers can pay by check, money order, or credit card. For more information visit GretanRifles.com.
Yet another .300 Blackout disaster. Unfortunately, that .300 Blackout cartridge can fit in a .223 Rem chamber. Shooting a .308-caliber bullet in .223 bore is a recipe for disaster.
The .300 AAC Blackout aka “300 BLK”, is a compact 30-caliber cartridge designed to work in AR-15 rifles. It has a shorter cartridge case to accommodate the bigger 30-caliber bullet while still fitting in a standard AR-15 magazine. Unfortunately, that’s the danger. A careless shooter can toss a .300 Blackout cartridge in with .223 Rem rounds without noting. And because the case-head size is the same as the .223 Rem (5.56×45) the rifle’s bolt assembly will happily chamber and fire the .300 BLK round. Problem is, that forces a .308 diameter bullet down an undersized .223-caliber bore. Not good!
This images were provided by Tactical Rifle Shooters on Facebook. The message was clear: “Don’t try to run 300 Blackout in your .223/5.56mm. It won’t end well. The problem is identical rifles and identical magazines but different calibers.”
For those who MUST have a .300 Blackout, here are some things you can do:
1. Use different colored magazines for .300 Blackout vs. .223 Rem.
2. Fit all your uppers with caliber-labeled ejection port covers.
3. Mark .223 Rem upper handguards with the caliber in bright paint.
4. Mark all .300 BLK Rounds with heavy black marker.
Comments by Folks Who Viewed these .300 Blackout Disaster Photos:
“The .300 Blackout is simply a badly-designed round. A properly-designed round would have had a feature in the shape that would have prevented cross loading in the first place.” — D. Santiago
“I almost made that mistake… I had a magazine of 300 BLK inserted in my .223/5.56 all night. Fortunately, I never pulled the trigger. Once I realized the mistake, I almost got ill. [After that incident] I no longer own a 300 BLK.” — B. Welch
“Happened to me hog hunting from a helo. Gun exploded in my face.” — B. Hood
“Fire-forming projectiles [is] so wrong in centerfire!” — M. Stres
“Had some dude come into the store the other day wanting .300 Blackout ammo to shoot in his 5.56 AR. It took 15 minutes of explaining for him to understand you got to have a .300 Blackout Upper!” — R. Williams
Do you use bushings to size your case-necks? Are you assuming that your bushings are actually round on the inside, with a hole that’s centered-up properly? Well you may be in for an unpleasant surprise, based on what our friend Jim de Kort recently discovered. Jim was concerned about the run-out on his brass. His cases went into his bushing-equipped FL die pretty straight, but came out of the die with up to .004″ run-out. “What gives?”, Jim wondered. “Could the problem be the bushings themselves?”
To answer that question, Jim decided to examine his bushings. Using an Accuracy One Wheel-drive concentricity gauge, Jim checked out some of his neck bushings. What he discovered may surprise you…
Neck Bushing Flaws Revealed
Trust no one… — Jim de Kort
Jim writes: “I measured the concentricity of my 6BR rounds today. I noticed they went into the neck-bushing equipped full-length sizing die with less than .001″ deviation but came out with .003-.004″. The culprit, it appears, was the bushing itself. Without it the cases stayed within .0005″ to .001″ deviation, so something was happening with the bushing.
One bushing had .00025″ deviation on the outside, yet almost .003″ on the inside, so it is crooked. But even when using a bushing that is within .001″ I still get .003″ runout after sizing. I repeated the same procedure for my 6×47 and got the same results. When using the bushing, concentricity suffers a lot.”
Before we bash the bushing-makers, we must acknowledge that many different things can contribute to excessive run-out and/or mis-alignment of case-necks. We don’t have all the answers here, and Jim would be the first to say that some mysteries remain. Still, these are interesting results that give all precision hand-loaders something to think about.
Jim Borden of Borden Accuracy also offers this tip: “Check the trueness of the face of the die cap. That has more to do with trueness than the bushing. Also check perpendicularity of hole in bushing to top surface. When I was making dies, the cap was made by threading and facing the threaded tenon in same setup.”
Editor’s Comment: Many people have great results with neck-bushing dies, but Jim isn’t the only fellow who has seen some very odd results. I personally employ honed, non-bushing dies for many of my chamberings. These non-bushing dies (with the necks honed for .002-.003″ neck tension) produce extremely straight ammo, with run-out consistently under .0015″.
Our take on Bore-Store Gun sleeves is simple: They work great, so buy them and use them — for ALL your valuable firearms.
These thick, synthetic-fleece sacks cushion your guns, preventing nicks and scratches. The breathable fabric wicks away moisture, and the fibers are coating with corrosion inhibitors. I personally use Bore-Stores for in-safe storage with all my guns, and I have never had one of my guns rust inside a Bore-Store, even when I lived a stone’s throw from the ocean.
Bore-Stores are offered in a wide range of sizes, so you can find something to fit everything from a Snub-nosed revolver to a 32″-barrelled 50 BMG. Rifle-size Bore Stores can be purchased for $12.00 – $21.00 from Brownells. For long F-Class or tactical rifles, we recommend the 10″x52″ Scoped Shotgun Bag, Brownells item 132-000-003. You can also order direct from the Bore-Store manufacturer, Big Spring Enterprises, www.BoreStores.com. Big Spring will also craft custom sizes on request.
Get Your Guns Out of Foam-lined Cases — They Are Rust Magnets
Just about the worst thing you can do for long-term storage (short of leaving your rifle outside in the rain) is to store firearms in tight, foam-padded cases. The foam in these cases actually collects and retains moisture from the air, acting as the perfect breeding ground for rust. Even in warm summer months, humid air can leave moisture in the foam.
Remember, those plastic-shelled cases with foam interiors are for transport, not for long-term storage. Don’t repeat the mistake of a wealthy gun collector I know. He stored four valuable Colt Single Action Army (SAA) revolvers in individual foam-padded cases, and locked these away in his gun safe. A year later, every one of his precious SAAs had rusted, some badly.
Consider Military-Style, Triple-Layer Bags for Long-Term Storage
While we prefer Bore-Stores for regularly-used guns, if you have heirloom firearms that will be kept in storage for very long periods without seeing any use, you may want to grease them up and place them in the thin, but rugged three-layer storage bags sold by Brownells. The bags are made from a three-layer laminate of polyester, aluminum, and polyethylene film, with a shiny silver exterior. Though the laminate is thin, the Brownells storage bags are puncture-resistant, and have a 0% moisture transmission rating so moisture can’t get inside. These bags are also resistant to petroleum-based chemicals and they won’t break down even in contact with soil or moisture.
Here’s one VITAL bit of advice for using these bags. Be absolutely sure, before you seal up the bags, that your guns are DRY and that all metal surfaces have been coated with an effective anti-corrosive, such as BoeShield T9 or Eezox. Brownells’ storage bags are inexpensive. A three-pak of 12″x 60″ rifle sacks (item 083-055-003WB) costs just $22.99 — under eight bucks a gun. That’s cheap insurance for rifles and shotguns that may cost thousands of dollars.
Is a ZERO extreme spread possible? Yes. Lou Murdica proved that, with AMP-annealed cases, and advanced reloading methods, you can achieve the exact same muzzle velocity — 2924 FPS for two shots in a row. Oh, and the accuracy wasn’t too bad either. Shooting in a tunnel with an F-Open rig on the bench, Lou put two rounds within 0.1 inch. Note, the rounds were fired with the wood-stocked F-Open/Benchrest rifle on the left, not the Rail Gun on the right. The full annealing and reloading process is shown in the video below:
See Complete Testing and Reloading Process in 3-minute Video!
We highly recommend you watch this video ALL the way through, and then watch it again. You will see one of the best shooters in the world loading precision ammo. Lou is a world-class short-range benchrest, long-range benchrest, and F-Class shooter. In this video you can see Lou load a cartridge start to finish, beginning with annealing using a computer-controlled AMP induction annealing machine.
After firing, the 6.5 Creedmoor case was annealed with the AMP induction annealer.
Here is Lou Murdica’s Reloading Procedure Used in this Test:
1. Anneal 6.5 Creedmoor cartridge in AMP Mk II Annealer.
2. Lubricate case with Imperial Case Wax.
3. Full-length size case with Redding FL bushing die in single-stage RCBS Big Max Press.
4. Apply Moly dry lube to inside of case-neck with brush.
After FL Sizing, and before bullet seating, Murdica applies dry Moly lube inside the case-neck.
5. Seat Primer with Bald Eagle Precision Primer Press.
6. Throw charge to within 1 kernel with Auto-Trickler System and Force Restoration Lab Scale.
7. Drop charge in case with precision funnel.
8. Seat bullet with hand die and Sinclair Arbor Press.
Two Rounds, Same Case, Both with Exact Same Velocity — 2924 FPS
If you watch the video, you can see that, for the second 6.5 Creedmoor round, the velocity is 2924 FPS. That is exactly the same velocity as shot number 1. So the two-shot Extreme Spread (ES) is Zero. The second shot was 0.1″ from shot number one — pretty close to one hole. Lou was using Vihtavuori powder and Berger AR bullets. On the screen, Oehler Ballistic Instrumentation software displays bullet velocities and impact locations using inputs from chronograph and acoustic target sensors.
Credit Boyd Allen for identifying Oehler System and RCBS Big Max Press.
Do you like the Chris Byrne bench at left? For more details, CLICK HERE.
FREE Bench Plans on the Web
Building your own portable shooting bench is a great do-it-yourself project. You can build a sturdy bench for well under $100 in materials. Compare that to some deluxe factory-built benches which may cost $600.00 or more. You’ll find a wide assortment of home-built shooting bench designs (both portable and fixed) on the internet. Renovation Headquarters has links to FREE Plans and building instructions for fourteen (14) different shooting benches. There are all-wood shooting bench designs as well as benches that combine a wood top with a metal sub-frame or legs.
Heavy Wood Bench That Converts to Three Sections for Transport
In addition to the fourteen benches mentioned above, here is an interesting break-down bench design. Call it a “semi-portable” bench. The legs and frame are made from stout 4×4 post segments so the bench is fairly heavy. However, this bench can break down into three (3) sections for easier transport to and from the range. Dado-cut channels assure proper top alignment. This might be a good choice if you plan a multi-day excursion to a location without fixed benches. This three-leg bench design can be made from easy-to-locate materials. Note: The dimensions of this bench are are larger than typical fixed benches to accommodate 50 BMGs and other big rifles. CLICK HERE for more details.
The folks at Applied Ballistics have a new toy — a large trailer filled with all the latest and greatest tech gear for testing long-range ballistics. Bryan Litz reported: “The maiden voyage for the AB Mobile Lab in Texas this week was a huge success! We look forward to supporting more long range shooting events.” Mitchell Fitzpatrick was there in the Lone Star state with fellow Applied Ballistics staffer Christopher Palka. The Applied Ballistics team will be trailering the Mobile Lab to Indiana where it will be on hand for the NRA National Championships at Camp Atterbury this month.
Ten rifles, heaps of cables, huge Doppler Radar unit, military-grade Laser RFs on tripods, spare barrels, safety gear — all ready for action in Texas.
About the Applied Ballistics Mobile Lab
Q: What is the basic purpose of the Applied Ballistics Mobile Lab?
Mitchell Fitzpatrick: The Mobile Lab allows us to effectively carry out ballistics testing in the field and at events. It has most of the capabilities of our normal lab, but on wheels.
Q: What hardware and electronics are carried in the Mobile Lab? What are its capabilities?
Bryan Litz: The Mobile Lab will transport most everything that’s in the main lab including the Doppler radar. This rig is new and we haven’t fully outfitted it yet. The load-outs will be somewhat flexible depending on the venue we are supporting.
The three rifles on the left are Barrett MRADS, $6000-$6154 MSRP, before optics.
NOTE to Readers — Check back at the end of the day. We will have more technical information from Bryan Litz and the Applied Ballistics team…
Need a new barrel for your Rem-actioned hunting or tactical rifle? Here’s a great DIY option for riflemen. McRee’s Precision offers 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. Most of the Pre-Fit barrels are 24″ long and threaded at the muzzle. CLICK Here for all Pre-Fit barrel specs.
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. And the price is under $500.00. Kits are currently available for these chamberings: 6.5 Creedmoor, 6mm Creedmoor, .243 Win, .308 Win, .308 Winchester Magnum. You can buy with confidence — McRee’s Precision offers a Half-MOA Accuracy Guarantee with its pre-fitted barrel kits.
The stainless steel Barrel Nut is set up for 1 1/16 x 16 barrel threads, while the stainless steel recoil lug has a 1/8 inch removable locator pin and is set up for 1.0625 dia barrel threads.
McRee’s Precision sells Rem-action Pre-Fit barrel packages (complete with barrel nut, recoil lug, and wrench) starting at $489.52. Choose from five chamberings: 6.5 Creedmoor, 6mm Creedmoor, .243 Win, .308 Win, and .300 Win Mag. These Pre-Fit barrel kits come 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 with standard go/no-go gauges, then torque the barrel nut against the lug. NOTE: You may require a barrel vise and action wrench to remove the original barrel. Chambering-specific headspace gauges required. Minor inletting changes may be needed forward of the action.
The folks at McRee’s Precision say their Pre-Fit system offers many advantages: “Remington Pre-Fitted Barrel Kits have become popular over the years. If Savage can do it, why not for our Remingtons? Our [Criterion-supplied] barrels are spec’d to the McRee standard of performance. There are several places to get the tools required to remove your factory barrel correctly. Once you have your barrel removed all you have to do is follow the normal Savage procedure to install your new barrel. We recommend that you contact your local gunsmith for the install. Feel free to call us with any questions.”
Product Tip from Ed LongRange. We welcome readers’ submissions.
You can do your own experimental calculations using JBM Online Ballistics (free to use). Here is an extreme example, with two printouts (generated with Point Blank software), one showing bullet trajectory at sea level (0′ altitude) and one at 20,000 feet. For demonstration sake, we assigned a low 0.2 BC to the bullet, with a velocity of 3000 fps.
One of our readers asked “What effect does altitude have on the flight of a bullet?” The simplistic answer is that, at higher altitudes, the air is thinner (lower density), so there is less drag on the bullet. This means that the amount of bullet drop is less at any given flight distance from the muzzle. Since the force of gravity is essentially constant on the earth’s surface (for practical purposes), the bullet’s downward acceleration doesn’t change, but a bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, the bullet behaves as if it has a higher ballistic coefficient.
Forum member Milanuk explains that the key factor is not altitude, but rather air pressure. Milanuk writes:
“In basic terms, as your altitude increases, the density of the air the bullet must travel through decreases, thereby reducing the drag on the bullet. Generally, the higher the altitude, the less the bullet will drop. For example, I shoot at a couple ranges here in the Pacific Northwest. Both are at 1000′ ASL or less. I’ll need about 29-30 MOA to get from 100 yard to 1000 yards with a Berger 155gr VLD @ 2960fps. By contrast, in Raton, NM, located at 6600′ ASL, I’ll only need about 24-25 MOA to do the same. That’s a significant difference.
Note that it is the barometric pressure that really matters, not simply the nominal altitude. The barometric pressure will indicate the reduced pressure from a higher altitude, but it will also show you the pressure changes as a front moves in, etc. which can play havoc w/ your calculated come-ups. Most altimeters are simply barometers that read in feet instead of inches of mercury.”
As Milanuk states, it is NOT altitude per se, but the LOCAL barometric pressure (sometimes called “station pressure”) that is key. The two atmospheric conditions that most effect bullet flight are air temperature, and barometric pressure. Normally, humidity has a negligible effect.
It’s important to remember that the barometric pressure reported on the radio (or internet) may be stated as a sea level equivalency. So in Denver (at 6,000 feet amsl), if the local pressure is 24″, the radio will report the barometric pressure to be 30″. If you do high altitude shooting at long range, bring along a Kestrel, or remember to mentally correct the radio station’s pressure, by 1″ per 1,000 feet.”
If you have been waiting to purchase a chronograph… now is a great time to buy. You can get the affordable MagnetoSpeed Sporter for under $180.00. You can set up this device in a few minutes, and you never have to go downrange to fiddle with a tripod or fuss with wires. The MagnetoSpeed Sporter is simple and effective — a no-hassle solution.
See MagnetoSpeed Sporter Chronograph Features Reviewed in Video
We’re impressed by the Sporter chrono, as are other shooters — this unit is very popular. Like the MagnetoSpeed V3, the Sporter faithfully records shots, even in complete darkness. Shot strings are recorded digitally and can be transferred to a smart phone via MagnetoSpeed’s XFR accessory (and Apps).
The MagnetoSpeed Sporter chrono is less than half the price of previous MagnetoSpeed models. This is big news for shooters who always wanted a MagnetoSpeed but found the $379.00 cost (for V3 model) too pricey. The new Sporter Chronograph costs just $179.00 at Brownells and $179.00 at Amazon.
The Magnetospeed Sporter offers most of the features of the more expensive models (see chart below for details) and has a updated sensor. MagnetoSpeed says its new Sporter is “Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers.” The Sporter Chronograph Kit (shown above) includes: Bayonet Sensor, 3.5 foot Data Cable, Remote Display (with Battery), Strap with thumb nut, Two V-block spacers, and compact storage box.
Q: Will the Sporter Chrono work with thicker barrel (i.e. greater than 1″ diameter)?
A: The manufacturer recommends the $399.00 V3 model for thicker barrels. But, wink-wink, if you have a 1.25″ barrel you can get this to work, based on what we’ve seen.. If you have a really fat barrel (up to 2.0″ diameter), get the V3. Magnetospeed also says the V3 is needed for airguns, shotguns, and muzzleloaders.
Click Image for Full-Screen Photo
The Sporter Chrono attaches quickly and easily. It has a 3.5-foot-long cord, and will work with Muzzle Brakes and Flash-hiders up to 2.7″ long.
Craters may look interesting on the moon, but you don’t want to see them on your primers. Certain mechanical issues that cause primer craters can also cause primer piercing — a serious safety problem that needs to be addressed. If you have a gun that is cratering primers (even at moderate pressure levels), there is a solution that works with many rifles — send your bolt to Greg Tannel to have the firing pin hole bushed.Firing Pin Hole Bushing by Greg Tannel
The 
Remember, those plastic-shelled cases with foam interiors are for transport, not for long-term storage. Don’t repeat the mistake of a wealthy gun collector I know. He stored four valuable Colt Single Action Army (SAA) revolvers in individual foam-padded cases, and locked these away in his gun safe. A year later, every one of his precious SAAs had rusted, some badly.
Here’s one VITAL bit of advice for using these bags. Be absolutely sure, before you seal up the bags, that your guns are DRY and that all metal surfaces have been coated with an effective anti-corrosive, such as BoeShield T9 or Eezox. Brownells’ storage bags are inexpensive. A 
One of our readers asked “What effect does altitude have on the flight of a bullet?” The simplistic answer is that, at higher altitudes, the air is thinner (lower density), so there is less drag on the bullet. This means that the amount of bullet drop is less at any given flight distance from the muzzle. Since the force of gravity is essentially constant on the earth’s surface (for practical purposes), the bullet’s downward acceleration doesn’t change, but a bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, the bullet behaves as if it has a higher ballistic coefficient.
