While Varget and Reloder 15 remain in short supply, you can often find IMR 4320 powder back in the shelves of local gun stores. IMR describes IMR 4320 as follows: “Short granulation, easy metering, and perfect for the 223 Remington, 22-250 Remington, 250 Savage and other medium burn rate cartridges.” This older-generation powder is more temp sensitive than the Hodgdon Extreme propellants, but in the right application, it looks to be a viable alternative for folks who can’t source Varget, Reloder 15, and even H4895.
IMR 4320 Shoots Well in the .308 Winchester
A while back, GS Arizona wrote an excellent Riflemans Journal article, IMR 4320 — the Forgotten Powder. GS developed IMR 4320 loads for his .308 Win Palma rifle and competed with IMR 4320-powered ammo at long range matches. He concluded that: “[IMR 4320] appears to be a very useful alternative to some of the harder-to-get powders. The load is working extremely well at 1000 yards. In the [2009] Arizona Palma State Championship, several high placing competitors were using the 4320 load. We got sub X-Ring elevation at 1000 yards from several rifles, and that’s all I’m looking for in a Palma load.”
IMR 4320 Works for Dasher Shooter
Forum member FalconPilot shoots a 6mm Dasher with Berger 105gr Hybrids. Looking for an alternative to Varget, he decided to give IMR 4320 a try. The results were good. FalconPilot reports: “I’ve been looking for other options (besides Reloder 15, which I love, but it’s really dirty). While at a gun shop in Ohio, I ran across 8 pounds of IMR 4320. I had never even heard of it, much less tried it. Getting ready for upcoming mid-range shoots, I loaded five rounds with IMR 4320 to the exact same specs as my winning Varget loads for the 6mm Dasher. This recipe was 32.7 grains of powder, Wolf SMR primer, Berger Hybrid 105 jumped fifty thousandths.” Falcon pilot tested his IMR 4320 load at 600 yards:
As you can see from the photo at the top of this article, FalconPilot had good results — a 1.5″ group at 600 yards. He reports: “This group was shoot during the middle of the day, mirage bad, scope set to 25X. It looks like IMR 4320 is a [very close] replacement for Varget… with a tad bit slower burn rate.” FalconPilot tell us the accuracy with IMR 4320 rivals the best he has gotten with Varget: “This gun has always shot under 2 inches [for 5 shots] at 600 yards, and most of time shoots 1.5 to 1.7 inches.”
For comparison purposes, here are Heat of Explosion and Burn Rate values from QuickLOAD for IMR 4320, and for the popular Reloder 15 and Varget powders. You can see that these powders have similar characteristics “by the numbers”:
Manufacturer
Powder Brand
Heat of Explosion
Burning Rate Factor
IMR
4320
3890
0.5920
Alliant
Reloder 15
3990
0.5200
Hodgdon (ADI)
Varget
4050
0.6150
WARNING — When changing from one powder to another, always start with manufacturer’s stated load data. Start low and work up incrementally. Never assume that loads will be equivalent from one powder to another, even powders with similar burn rates.
What Other Forum Members Say:
I was using IMR 4320 in the mid 70s in my .222 Rem. Darned great powder and I never had a load that was not accurate from the .222 to .30-06 with that powder. — 5Spd
A fine powder overshadowed by the nouveau wave of “gotta have the newest — make me a better shot” powders. Try 4320 in a 22-250 — what a well-kept secret! IMR 4320 meters very well and is a flexible alternative to many of the hard-to-find powders so much in demand. — AreaOne
IMR 4320 was my “go to” powder in my .223 for many many years. This powder and Winchester 55gr soft point bulk bullets (the cheapest bullet I could buy at the time) accounted for thousands of prairie dogs, coyotes, and anything else that needed shooting. I still use IMR 4320 in some .223 loads and am very happy with it still. — pdog2062
I’ve been using it in a .308 Win for several years. I think it is very sensitive to temperature and always waited till the last minute to load my ammo with a close eye on the weekend forecast at the range. IMR 4320 Works pretty good for 155gr Palma and 168gr Hybrid [bullets] in my .308. — JayC
Surgeon Rifles makes excellent tactical actions and complete rifles. Now you can save 10% off all Surgeon products (actions, rifles, bottom metal, bipods, suppressors etc.) with Coupon Code SR10. The sale even includes optics (if purchased with a complete rifle).
Surgeon recently marked 10 years in business, and the company now has 10,000+ Facebook fans. To celebrate those milestones, Surgeon has announced a special Customer Appreciation Sale:
Now through August 31st, all Surgeon Rifles’ products* are 10% off MSRP! That means EVERYTHING! In-stock rifles, custom rifles*, actions, bottom metals, bolt knobs, bi-pods, small parts, apparel, and AWC suppressors** are all on sale. Surgeon is even extending 10% off MSRP to all optics that we offer when purchased with a rifle.
All you have to do is use coupon code SR10 during online checkout, or mention this sale to Surgeon’s sales reps. NOTE: Discount cannot be combined with any other offers, deals, or discounts including MIL/LE or dealer pricing. The 10% off does not include tax or shipping.
*Custom rifles must be ordered and deposit received by 5:00 pm MST, August 31st, 2015.
**Only valid on AWC Silencers’ PSR, THOR PSR, Thundertrap, THOR Thundertrap, Raider, and THOR Raider models.
Sale tip from EdLongrange. We welcome reader submissions.
What we now know as the “6mm Remington” was originally called the .244 Remington. The cartridge was renamed because it was not a commercial success initially, being eclipsed by the .243 Winchester. The .244 Remington and the 6mm Remington are identical — only the name was changed. Why was the .244 Remington an “also-ran” to the .243 Win? Sierra Bullets Ballistics Technician Paul Box provides some answers…
The year was 1955. A time of carhops, drive-in movies, and Buffalo Bob. It was also the year that Winchester introduced the .243 Win and Remington counter-punched with the .244 Remington (now more commonly known as the 6mm Remington). The .243 Win was based off the time-proven .308 Win case while Remington chose the old war horse, the 7×57.
We’ve all read countless times how Winchester chose the 1:10″ twist, while Remington adopted the 1:12″ twist for their .244 Rem rifles. The first complaint in the gun magazines of that era was how the faster twist Winchester could handle 100 grain bullets, while Remington’s [12-twist factory rifles were supposedly limited to 90 grain bullets].
The first complaint I remember reading was that the 100-grainer was better suited for deer-sized game and the 1:12″-twist wouldn’t stabilize bullets in this weight range. Now, let’s look at this a little closer. Anybody that thinks a 100-grainer is a deer bullet and a 95-grainer isn’t, has been drinking too much Kool-aid. In all honesty, it’s all about bullet construction and Remington had constructed the [90s] with light game in mind. In other words, Remington got it right, but due to a lack of knowledge at the time on both bullet construction and stability, the .244 never gained the popularity it deserved. At that time, Sierra had the 100gr SMP and Hornady offered a 100gr RN that would both stabilize in the slower 1-12″ twist. The .244 Remington provides another classic example of how the popularity of a cartridge suffered due to a lack of knowledge.
.244 Rem vs. .243 Win — What the Experts Say
Respected gun writer Chuck Hawks says the .244 Remington deserved greater acceptance: “The superb 6mm Remington started life in 1955, the same year as the .243 Winchester. It was originally named the .244 Remington. Although the 6mm lost the popularity contest to the .243, it is one of my favorite rifle cartridges, and much appreciated by reloaders generally. The .244 Rem and 6mm Rem cartridges are completely interchangable, and anyone with a .244 Rem rifle can shoot [6mm Rem] ammunition in complete safety (or vice-versa). Remington .244 rifles made from 1958 on can stabilize all 6mm bullets, while those made in 1955 through 1957 are limited to loads using spitzer bullets not heavier than 90 grains for best accuracy.”
Nathan Foster, author of The Practical Guide to Long Range Hunting Cartridges, states: “In 1963 Remington attempted to regain ground by releasing .244 rifles with a new 1:9″ twist to handle heavier bullets. The cartridge was renamed the 6mm Remington and new ammunition was loaded giving the hunter the choice of either an 80gr bullet for varmints or a 100gr bullet for deer. In comparison to the .243 Win, factory loads for the .244/6mm Remington are slightly more powerful while hand loads increase this margin further.”
Was the .244 Remington Actually Better than the .243 Winchester?
The .244 Remington (aka “6mm Remington”) has a velocity advantage over the .243 Winchester due to a slightly larger case capacity. The longer case neck of the .244 Remington is considered desirable by handloaders. We like the added capacity and long neck of the original .244 Remington. As renamed the “6mm Remington”, the cartridge HAS developed a following, particularly with varmint hunters looking for a high-velocity 6mm option. But it never achieved the success of the .243 Winchester for many reasons. As a member of the .308 family of cartridges, the .243 Winchester has certain obvious advantages. First, you can simply neck down .308 Win brass, which was available at low cost from many sources. Moreover, a .308 Win or 7mm-08 full-length sizing die could be used for body sizing. Still the .244 Remington (6mm Remington) presents an interesting “what if?” story…
Many tactical shooters have adopted the .260 Remington as an alternative to the heavier-recoiling .308 Winchester. The .260 Rem has also performed well in the hands of long-range High Power shooters such as SSG Sherri Jo Gallagher, past National High Power Champion. The .260 Remington is basically the .308 Win necked down to .264 (6.5 mm) caliber. It can launch very high-BC 130-142 grain projectiles at impressive velocities. The ballistics of the .260 Rem allow it to shoot flatter, with less wind drift, than typical .308 Win loads.
For fans of the .260 Remington, very high-quality factory ammo is now available. ABM Ammo, a division of Berger Bullets just announced that it will produce two varieties of .260 Remington ammo.
ABM’s 260 Remington 140gr Berger Match Hybrid Target ammo is designed for class-leading ballistic and superior accuracy. Using the highest-BC 6.5 mm caliber bullet offered by Berger, the 140gr Hybrid, this load features less wind deflection and more energy on target than the competition. ABM claims that this Match Hybrid ammo is “unrivaled as a long-range 260 Remington factory ammo option.” Since it pushes a higher-BC bullet than other .260 Rem factory ammo, we’d have to agree with that statement.
Performance based on a 26″ barrel and sea level conditions.
Mission Ready .260 Rem OTM Tactical Load for Mag-Fed Rifles
ABM Ammo also offers .260 Rem factory ammo loaded with the NEW 130gr AR Hybrid bullet. The .260 Rem 130gr Berger Match AR Hybrid OTM Tactical load is optimized for the AR-10 platform or any magazine-fed rifle. Berger’s 130gr AR Hybrid bullet offers a 0.290 G7 BC. That’s very close to the 0.317 BC of the longer 140gr Hybrid. This, combined with a 2847 FPS muzzle velocity, provides excellent performance in a shorter COAL that feeds perfectly from box magazines.
In fact, if you run the ballistics (using JBM) using ABM’s published MVs, you’ll find that you give up nothing with the shorter bullet. At 600 yards, the 130gr “Mission Ready” load has 78.8″ (12.5 MOA) of drop. By comparison, the “Match Ready” load with 140-grainers has 80.3″ (12.8) MOA of drop at 600 Yards (That’s not a mistake — the smaller bullet has LESS drop because it has a higher MV to start.) At 1000 yards, the “Mission Ready” load is virtually identical to the “Match Ready” load: The 130gr ammo has 304.6″ (29.1 MOA) of drop at 1000 vs 303.4″ (29.0 MOA) for the 140gr ammo at the same distance. (These calculations are based on standard conditions at sea level, with ABM supplied MVs.)
Because the ballistics are so close, you may want to try both loads in your .260 Rem rifle, even if you single-load and are not restricted by mag length. Some barrels may have a preference for one bullet over the other.
Product Tip from EdLongRange. We welcome reader submissions.
The .260 Remington and the 6.5×55 Swedish (aka 6,5x55mm SE) are both very popular cartridges with hunters and target shooters. The 6.5×55 has a long military heritage and a great record as a hunting round. The .260 Rem, essentially a .308 Win necked down to .264 caliber, is a more recent cartridge, but it grows in popularity every year, being one of the top cartridges for tactical/practical competitions. It offers better ballistics and less recoil than the parent .308 Win cartridge. In our Shooter’s Forum, respected UK gun writer Laurie Holland provided a good summary of the differences between the two chamberings. Laurie writes:
The 6.5×55 case has 6 or 7% more capacity than the .260s, even more in practice when both are loaded to standard COALs with heavy bullets, which sees them having to seated very deep in the .260 Rem using up quite a lot of powder capacity. So loaded up for reasonable pressures in modern actions, the 6.5×55 will give a bit more performance.
The issue for many is what action length is available or wanted, the 6.5×55 requiring a long action. So sniper rifle / tactical rifle competitors will go for the .260 Rem with the option of the many good short-bolt-throw designs around with detachable box magazines (DBMs). If a bit more performance is needed, the .260 AI (photo right) can yield another 100-150 fps velocity, depending on bullet weight.
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)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. With a barrel reduction from 28″ to 16.5″, the average speed loss of the four types of .308 ammo was 261 fps total. That works out to an average loss of 22.7 fps per inch. This chart shows velocity changes for all four ammo varieties:
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
The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Since we would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut, we decided to eliminate gathering data on group sizes. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 47° F.”
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.
Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .308 barrel cut-down test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33″ to 28″, we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5″ longer than Rifleshooter.com’s .308 Win start length. Velocity loss can be more extreme with shorter barrel lengths (and bigger cartridges). Powder burn rates can also make a difference.
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.
Gavin Gear tests .308 ammo with his DPMS LR-308B, AR10-type rifle.
Our friend Gavin Gear of UltimateReloader.com owns a DPMS LR-308B, an AR10-type semi-auto rifle. Gavin finds that his DPMS has a healthy appetite for ammunition. So, he set up his Hornady Lock-N-Load progressive press to produce .308 Win ammo. This video shows the process of press set-up and operation, complete with Hornady’s automated Case Feeder and Bullet Feeder. Employing elevated rotary hoppers, the case feed and bullet feed systems really speed up production. The automated feeders allow the operator to produce cartridges without ever touching case or bullet with his hands.
If you need large quantities of .308 Win ammo for 3-Gun matches or tactical games, and if you value your time, a progressive press may be a wise investment. The progressive can load a complete round with every cycle of the press handle. With Case Feeder and Bullet Feeder in place, the Hornady L-N-L can easily crank out a new .308 round every 3-4 seconds (watch video at 5:25). Conservatively speaking, that’s 15 rounds per minute sustained production (and some guys can go even faster).
Get updates from UltimateReloader.com via Gavin’s twitter feed: @UReloader. To learn more about the Hornady Lock-N-Load Progressive Press (with case/bullet feed options), and to see a list of the dies and accessories Gavin uses, click the link below:
When we recently ran a story about Dennis Santiago’s new snakeskin Eliseo Tubegun, folks asked us if this kind of rifle can be competitive in F-Class competition. Here’s a detailed answer to that question by G. Salazar, who runs the Riflemans Journal Website.
A while back, G. Salazar published a three-part article on Shooting The Tubegun in F-Class. Links for all three segments are found below. The article covers some of the hardware German engineered to adapt his tubegun for long-range F-Class shooting with scope. If you’re an F-Classer, or just a fan of tubeguns, you should read German’s article, in all its parts.
In the intro to his multi-part F-Class Tubegun article, German explains:
Salazar: The tubegun has truly changed the face of High Power shooting over the past five years or so. Specifically, the CSS (Gary Eliseo) tubeguns, which are made for a broad variety of actions and configurable to single-shot or repeater, have truly helped the sport to grow. That’s not just idle talk, the two principal factors that made the tubegun so important to our growth are the ease of transition for AR15 shooters moving into a bolt-action rifle and the absolutely ridiculous length of time it currently takes to get a stock from the conventional stock makers. My last conventional stock took well over two years from order to delivery (plain fiberglass). One of my friends has now been waiting four years for a simple wood stock for a smallbore rifle. By contrast, tubeguns, which are largely CNC machined, are delivered in a reasonably short time — weeks or a couple of months at most.
Notwithstanding the foregoing, the tubegun would never have attained its present success if it weren’t for one simple fact — they are brutally accurate. I have three CSS tubeguns, one chambered in .308 and two in .30-06 and they are my favorite prone rifles due to their accuracy and great ergonomics. Those factors are just as appealing to an F-Class competitor as to a prone shooter, and indeed, the tubegun is making solid inroads into F-Class. READ MORE…
Giraud Tool has a new case trimmer/chamferer that works with a power drill (or other power source). Giraud’s patent-pending Tri Way Case Trimmer is a self-contained unit powered by your drill or motor. Using a sharp carbide blade it will trim your cases to length, deburr, and cut both inside and outside chamfers — all in one pass. That’s pretty impressive for a $90 tool that fits in the palm of your hand.
Close-up of the Tri Way cutter with clear plastic chip guard removed.
Product Features
1. Fully adjustable for cartridge length (and depth of chamfer).
2. Tool includes carbide blade that cuts a 15° inside case mouth chamfer and 45° outside chamfer.
3. Case holder supported by sealed ball bearing raceway.
4. Tool includes removable, transparent plastic chip guard.
5. Tool can work in any orientation (vertical, horizontal, or any angle).
The Giraud Tri Way Trimmer is designed to be powered by a portable hand drill, drill press, or other dedicated rotating power source. The tool indexes off the shoulder of your cases, but the blade adjusts so that cartridge overall length (COAL) can be controlled with precision. Constructed out of 6061-T6 aluminum and 303 stainless steel, the Tri Way tool should last a lifetime. Note: This tool is not universal. The Tri Way is dedicated to a single cartridge and “related” cartridges with similar body dimensions. Thus you need a specific tool for each cartridge family. For example, the .308 Win tool will also trim .243 Win, .260 Rem, and 7mm-08.
Cartridge Sizes Available for Giraud Tri Way Trimmer:
.223 Remington (Also trims .17 Remington, .204 Ruger, .222 Remington, .222 Remington Magnum)
7.62 x 39mm (Russian)
.300 Blackout (Also trims .17 Rem Fireball, .221 Fireball)
.308 Winchester (Also trims .243 Winchester, .260 Remington, 7mm-08)
.30-06 Springfield (Also trims .25-06, .270 Winchester, .280 Remington)
.300 Winchester Mag (Also trims .264 Winchester Magnum, 7mm Remington Magnum)
Product Tip from EdLongrange. We welcome reader submissions.
While Varget and Reloder 15 remain in short supply, you can often find IMR 4320 powder back in the shelves of local gun stores. IMR describes IMR 4320 as follows: “Short granulation, easy metering, and perfect for the 223 Remington, 22-250 Remington, 250 Savage and other medium burn rate cartridges.” This older-generation powder is more temp sensitive than the Hodgdon Extreme propellants, but in the right application, it looks to be a viable alternative for folks who can’t source Varget, Reloder 15, and even H4895.
The 6.5×55 case has 6 or 7% more capacity than the .260s, even more in practice when both are loaded to standard COALs with heavy bullets, which sees them having to seated very deep in the .260 Rem using up quite a lot of powder capacity. So loaded up for reasonable pressures in modern actions, the 6.5×55 will give a bit more performance.
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.”
