Many short-range Benchresters have thought about converting their 6 PPC to shoot a 30BR for score matches, or a Dasher for mid-range (or even 1000-yard) games. That way you have a rifle that does double duty, giving you the most bang for your buck. Though an action with a PPC bolt won’t normally work with 30BR/6BR/Dasher cases with their larger .308-class rim (0.4728″ diameter), there is a pretty easy solution that allows you to cycle these bigger cartridges with a 6PPC-style bolt (designed to fit .220 Russian rims).
“Rebating case rims … lets you shoot a 30BR in score matches using your PPC action. All you need is a new barrel. This saves buying another bolt, receiver, or rifle.” — Butch Lambert
Butch Lambert of ShadeTree Engineering provided this tip. Butch notes that many 6 PPC benchrest group shooters also enjoy shooting in score matches. But to be really competitive in the BR for score game, that means shooting a 30BR, which has a wider, .308-class rim (0.4728″ diameter). Likewise, if you want to compete in 600-yard registered BR events or in varmint matches, you probably want to run a bigger case, such as the 6BR, 6mm Dasher, or 6-6.5×47. Those cartridges also have the larger 0.4728″ rims.
To convert a PPC-boltface action to shoot the bigger cases you can spend a ton of money and buy a new bolt. That can cost hundreds of dollars. The simpler solution is to turn down the diameter of the larger cases on a lathe. Butch explains: “We’ve seen plenty of interest in rebating case rims. This lets you shoot a 30BR in score matches using your PPC action. All you need is a new barrel. This saves buying another bolt, receiver, or rifle if you have a PPC boltface. Anyone who has access to a lathe can do this job pretty easily. Yesterday I turned 150 case in about an hour.” Below is the lathe form tool Butch uses to rebate the case rims.
Cutting Head for Rebating Rims
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Here’s great news for mid-size cartridge fans, and especially PRS and tactical shooters. Lapua just announced it will produce 6.5 Creedmoor cartridge brass, which should be available in the first quarter of 2017. This premium-quality brass features a small primer, and 1.5mm flash hole (as found on Lapua’s 6mmBR, 6.5×47 Lapua, and 220 Russian brass). We expect Lapua’s 6.5 Creedmoor brass will set new standards for accuracy and case life for this popular mid-sized cartridge. Of course Lapua’s new 6.5 Creedmoor brass can also be necked down and loaded in 6mm Creedmoor configuration. With the small primer pocket and proven strength of Lapua brass, we think 6.5 Creedmoor shooters will see enhanced cartridge velocities with the ability to maintain tight primer pockets even with very stout loads. And we expect accuracy to be on a par with Lapua’s excellent 6.5×47 Lapua brass. Taken together, this is an exciting product release. Here is Lapua’s official announcement:
We are happy to announce the addition of the 6.5 Creedmoor case to the Lapua line! Despite a relatively short time on the marketplace, the 6.5 Creedmoor has made a tremendous splash in the field, rapidly becoming one of the most requested cases we hear about from shooters. Lapua’s 6.5 Creedmoor is designed to function in a short action, which is also a plus for hunters, vitally concerned with the rifle’s weight and compactness. In fact, many of the same features which make for a successful competition cartridge, translate nicely to the hunting fields as well.
For most species of mid-size game such as deer or boar, the Creedmoor will prove to be a deadly performer. And while the selection of high grade Match bullets in the 6.5 bore size is tremendous, there’s no shortage of exceptionally good hunting bullets either. The 6.5s as a group have always been known as excellent performers on game.
Made with Lapua’s typical dedication to precision, our new 6.5 Creedmoor case has been refined just a bit, to make it an even better performer. We’ve opted for the small rifle primer, which normally produces an optimized ignition and better accuracy than large primers in mid-sized cartridges like the Creedmoor.
We’ve also incorporated our smaller-diameter flash hole (1.5mm, rather than the industry-standard 2.0mm), which has proven to provide enhanced accuracy, and is used in a number of our other accuracy-oriented cases. In this respect, the new 6.5 Creedmoor joins the ranks of our other dedicated accuracy cartridges such as the .220 Russian (6mm PPC), the 6mmBR Norma, the 6.5×47 Lapua, and the .308 Win Palma cases.
And naturally, the new 6.5 Creedmoor will be made with our well-known Passion for Precision. Strictest control over the metallurgy, the forming and drawing processes, precise annealing all performed under the watchful eyes of our production experts. For you, the handloader, that means the durability for which our cases are famous, combined with consistency and long life. Already proven in competition, we predict that the 6.5 Creedmoor will be a force to be reckoned with for many years to come.
Comment on Lapua’s new 6.5mm Creedmoor
Our British friend Laurie Holland was excited about the new 6.5 Creedmoor brass from Lapua: “With this and Peterson Cartridge on the bandwagon, plus another U.S. brass maker… the Creedmoor’s momentum is becoming impressive.” Laurie observes: “A small primer Lapua-cased 6.5mm Creedmoor is in effect a 6.5X47 Lapua ‘Improved’!” That’s a pretty interesting concept indeed. Which makes us wonder if the .260 Remington has finally been fully eclipsed. With Lapua 6.5 Creedmoor brass you can probably get very, very close to .260 Rem performance in a much more efficient case.
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Many visitors to the site ask us, “I’ve got a .223 and .308. What will a 6mmBR Norma (6BR) give me that I’m not getting already?” Well first you will probably average consistently smaller groups than your current .223 or .308 rifle (assuming the 6BR has a quality barrel and trigger). A good .308 Winchester can be superbly accurate, no question about that, but the lesser recoil of the 6BR works in the shooter’s favor over a long string of fire. Even with a Rem 700 or Savage action factory action, a 6BR with a benchrest stock, premium barrel, and a high-quality chambering job should deliver 5-shot groups in the high twos to mid-threes, provided you do your job. We have one 6BR rifle that shoots Lapua factory-loaded 6BR ammunition in the low twos and high ones. That’s exceptional, we admit, but it still shows how the 6BR is an inherently accurate cartridge, even with factory loads.
Compared to a .223, the 6BR offers a much better selection of high-BC projectiles, and will deliver considerably more power on the target. Compared to the .308 shooting 168gr MatchKings, a 6BR shooting 105-107gr bullets offers better ballistics all the way out to 1000 yards. Plus, for most people, the 6BR is just easier to shoot than a .308. Recoil is less than half of the .308 cartridge. Both the .308 and 6BR chamberings offer good barrel life, but the 6BR uses 15-18 grains less powder, saving you money. On the other hand the .308 is the designated cartridge for F-TR and Palma shooting, so it may be a more versatile chambering for Long-Range competition. So which would we choose between the 6BR and the .308? Actually we think you should have both. The 6BR is my favorite cartridge out to 500 yards, and I like the .308 Win for F-TR. And… if you want to shoot at the World Fullbore Championships this week at Camp Perry there’s only one choice — a .308 Win.
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We first ran this story a few years back. But it’s still a very interesting subject for benchrest shooters. Shown above, the 30 BR (a 6mmBR necked up to .30 Caliber) currently rules the benchrest-for-score game. However, a 30 BR Improved offers some potential advantages, particularly when the winds are strong or tricky. In this article Al Nyhus explains his 30 BRX wildcat. Running Hodgdon H4198, Al says he gets an easy 150 -200 FPS more than the conventional 30 BR. That can translate to less drift in the wind. It also lets you pursue a higher speed node, which can lead to improved accuracy with some barrels.
Forum member Al Nyhus is a top-level score shooter who has competed successfully with the 30 BR cartridge in VFS (Varmint for Score) matches. Al has been working on an “improved” 30 BR cartridge that delivers extra velocity. Al’s 30 BRX cartridge is inspired by the 6mm BRX cartridge, popular in 600-yard benchrest and across-the-course competition. The 6mm BRX cartridge maintains the same sidewall profile and shoulder angle as the parent 6mmBR case. Likewise, the 30 BRX retains the 30° shoulder used on the popular 30 BR cartridge.
Al reports: “Thought you might like to see what I’ll be working with in my VFS gun this season. It’s a true 30 BRX — a 30 BR with the shoulder moved forward 0.100″ with the standard BR shoulder angle. Stan Ware of SGR Custom Rifles built one last season for Steve Grosvenor and I was really impressed by the performance of Steve’s gun. The 30 BR barrel on my VFS gun needed replacing, so the new 30 BRX got the nod.”
30 BRX Delivers 150-200 FPS More Velocity than 30 BR
Al says his 30 BRX gives a solid 150-200 fps speed gain over the 30 BR at the top, while needing just 2.5-3.0 more grains of Hodgdon H4198 to do so. A 30 BR case holds on average 40.8 grains of water, while the 30 BRX holds 42.3 grains (roughly 4% more). So the 30 BRX delivers a 7% increase in velocity with a mere 4% increase in H20 capacity. That’s pretty good efficiency. [Editor’s Note: Assuming 34 grains of H4198 is a typical 30 BR match load, Al’s increase of 2.5-3.0 grains for the 30 BRX represents roughly a 7.5-8.5% increase in actual powder burned. That explains the higher velocities.]
Why did Nyhus decide to try an “improved” 30 BR?
Al explains: “The 30 BRX was created to operate at a [higher] velocity level than can be achieved with the standard 30 BR case, while at the same time keeping the easy-tuning characteristics of the standard 30 BR case. We also wanted to use the same powders currently used with the 30 BR and maintain similar operating pressures.” Is the 30BRX harder to shoot because of the increased velocity? Al doesn’t think so: “In a 13.5-lb HV gun, the 30 BRX case is a pleasure to shoot with just a flea bite of recoil.”
Will the 30 BRX Replace the 30 BR in Score Competition?
The 30 BR is already an exceptionally accurate cartridge that dominates short-range Benchrest for Score competition. Will the 30 BRX make the standard 30 BR obsolete? Nyhus doesn’t think so. However, Al believes the 30 BRX offers a small but important edge in some situations: “On any given day, it’s the shooter that hits the flags best and makes the fewest mistakes that ends up on top. No amount of velocity will save you when you press the trigger at the wrong time. Missing a switch or angle change at 200 yards that results in 3/4″ of bullet displacement on the target can’t be compensated for with another 200 fps. That’s the hard fact of benchrest shooting. But on those days when, as Randy Robinett says, ‘our brains are working’, the BRX may offer enough of an advantage to turn a close-but-no-cigar 10 into an ‘X’ at 200 yards. Or turn a just-over-the-line 9 into a beggar 10.” Given the fierce competition in Score matches, an extra 10 or another X can make the difference between a podium finish and also-ran status.
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How well can the 6mm Dasher perform at 1000 yards when conditions are good, and the shooter is riding a hot streak? Well here’s a shot-by-shot record of Scott Nix’s 4.554″ 10-shot group shot at Missoula, Montana at the Northwest 1000-yard Championship a few years back. All 10 shots were centered for a 100-6X score. That’s about as good as it gets. If Scott had stopped after 5 shots, his group would have been under 3 inches!
Video Demonstrates Amazing 1000-Yard Accuracy
Watch the video. You can see the group form up, shot by shot. It’s pretty amazing. Scott’s first shot (at the 45-second mark of the video) was right in the X-Ring, and four of Scott’s first five shots were Xs. That’s drilling them! This video was recorded from the pits at the 1000-yard line, during record fire.
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In our Shooters’ Forum, you’ll find a lengthy thread about accuracy problems with a Savage LRPV, chambered in 6mmBR. The gun would repeatedly split groups at 100 yards, and at 300 yards, the “flyers” would open up the groups to 1.5 MOA or larger. Interestingly, the factory test target (at right) showed a split group — not a good sign.
The gun’s owner, forum member LR_Shooter, tried a variety of tweaks: “I did this, done that… [changed] torque, tang floated, bedded action, recut chamber, and [adjusted firing pin]”. But nothing really helped. Frustrated, LR_Shooter asked his fellow Forum members for help. Much advice was proffered, including the novel idea of removing the middle action screw in the Savage 3-screw target action. Some of the advice proved helpful, but none of the suggested remedies produced a major improvement. This rifle, out of the box, tossed flyers and no amount of tweaking (or changes in shooting technique) really cured the basic problem. That is, until, the factory barrel got replaced…
New Criterion Pre-Fit Barrel Works Wonders
LR_Shooter acquired a Criterion pre-fit barrel from Jim Briggs at Northland Shooters Supply (NSS). These pre-fits are designed for easy installation with the standard Savage barrel nut. Wouldn’t you know it, with a new 30″ heavy-contour barrel on the LRPV, the gun started shooting way better. No more crazy fliers, no more split groups, no more excessive vertical. And the improvement came without any other major modifications. LR_Shooter reports: “I got a replacement barrel from Jim at NSS. It is a 30″ bull Criterion barrel. So far, without playing with torque screws and having my old setup… I’m very satisfied with the barrel I got. Now I have no problem getting [groups] under 0.25 MOA. Finally this thing can shoot!” The targets below, shot with the new Criterion barrel, speak for themselves. The left target was shot at 100 yards, while the target on the right was shot at 300 yards (very impressive).
Targets Shot with Savage LRPV Fitted with Criterion Barrel
Moral of the Story — Sometimes A New Barrel Really Is the Right Solution
All of us have struggled at times with a rifle that won’t live up to expectations. This Editor personally struggled for over a year with a .260 Rem Savage with a factory tube. The gun tended to split groups and the POI walked as the barrel heated. I tried one powder/primer combination after another, working through a variety of seating depths over many months. I was persistent. Out of stubbornness, I just believed that sooner or later I’d find the magic load.
Well folks, sometimes there’s really nothing you can do about a sub-par barrel. It is what it is. To really improve a gun’s accuracy (particularly a gun with a factory tube), you may need to open your wallet and get a quality aftermarket barrel. Spending months trying one recipe after another may simply be an overwhelming waste of powder, bullets, and your precious time.
Albert Einstein supposedly said: “Insanity is defined as doing the same thing over and over again, and expecting different results.” Well that sort of describes my efforts with my .260 Rem. Once I had enough evidence that my barrel split groups no matter what load combo (and seating depth) I tried, it was time to pony up for a new barrel. When I did finally screw on a nice PacNor 3-groove Supermatch, that Savage suddenly became a true tack-driver. As re-chambered in 6mmBR with the Pac-Nor, in calm conditions, my Savage will now consistently shoot in the twos with heavy bullets, and it can sometimes dip down into the ones with Berger 80gr flat-base bullets. The moral of the story here is simple — don’t waste weeks or months chasing your tail with a barrel that just won’t deliver (after a reasonable amount of testing). Save up for a custom barrel, get it chambered properly, and stop your cycle of frustration.
Contact Information for Northland Shooters Supply:
E-mail: briggs.j-b@q.com (that is Q.com not G.com)
Phone: (763) 682-4296
Fax: (763) 682-6098
Mailing address:
P.O. Box 333
Buffalo, MN 55313
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When a rifle isn’t shooting up to it’s potential, we need to ask: “Is it the gun or the shooter?” Having multiple shooters test the same rifle in the same conditions with the same load can be very revealing…
When developing a load for a new rifle, one can easily get consumed by all the potential variables — charge weight, seating depth, neck tension, primer options, neck lube, and so on. When you’re fully focused on loading variables, and the results on the target are disappointing, you may quickly assume you need to change your load. But we learned that sometimes the load is just fine — the problem is the trigger puller, or the set-up on the bench.
Here’s an example. A while back we tested two new Savage F-Class rifles, both chambered in 6mmBR. Initial results were promising, but not great — one gun’s owner was getting round groups with shots distributed at 10 o’clock, 2 o’clock, 5 o’clock, 8 o’clock, and none were touching. We could have concluded that the load was no good. But then another shooter sat down behind the rifle and put the next two shots, identical load, through the same hole. Shooter #2 eventually produced a 6-shot group that was a vertical line, with 2 shots in each hole but at three different points of impact. OK, now we can conclude the load needs to be tuned to get rid of the vertical. Right? Wrong. Shooter #3 sat down behind the gun and produced a group that strung horizontally but had almost no vertical.
Hmmm… what gives?
Shooting Styles Created Vertical or Horizontal Dispersion
What was the problem? Well, each of the three shooters had a different way of holding the gun and adjusting the rear bag. Shooter #1, the gun’s owner, used a wrap-around hold with hand and cheek pressure, and he was squeezing the bag. All that contact was moving the shot up, down, left and right. The wrap-around hold produced erratic results.
Shooter #2 was using no cheek pressure, and very slight thumb pressure behind the tang, but he was experimenting with different amounts of bag “squeeze”. His hold eliminated the side push, but variances in squeeze technique and down pressure caused the vertical string. When he kept things constant, the gun put successive shots through the same hole.
Shooter #3 was using heavy cheek pressure. This settled the gun down vertically, but it also side-loaded the rifle. The result was almost no vertical, but this shooting style produced too much horizontal.
A “Second Opinion” Is Always Useful
Conclusion? Before you spend all day fiddling with a load, you might want to adjust your shooting style and see if that affects the group size and shape on the target. Additionally, it is nearly always useful to have another experienced shooter try your rifle. In our test session, each time we changed “drivers”, the way the shots grouped on the target changed significantly. We went from a big round group, to vertical string, to horizontal string.
Interestingly, all three shooters were able to diagnose problems in their shooting styles, and then refine their gun-handling. As a result, in a second session, we all shot that gun better, and the average group size dropped from 0.5-0.6 inches into the threes — with NO changes to the load.
That’s right, we cut group size in half, and we didn’t alter the load one bit. Switching shooters demonstrated that the load was good and the gun was good. The skill of the trigger-puller(s) proved to be the limiting factor in terms of group size.
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Need top-quality 6mm match bullets for your 6mmBR, 6mm Dasher, 6XC, 6mm Creedmoor, 6-6.5×47, or .243 Win? Then get out your checkbook, because this is a very good deal on hard-to-find Berger 6mm 105gr Hybrid Match Bullets.
Right now Precision Reloading offers big, 500-count boxes of 105gr 6mm Hybrids for just $159.99. That works out to just $31.99 per 100, a lot less than you’d pay normally. These .243-diameter premium bullets hold many records and have won many important shooting competitions. You may want to act quickly — supplies are limited. When Precision Reloading runs out of sale inventory, prices will go up. To order, visit PrecisionReloading.com
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Estimating Actual Cost per Round by Caliber
This article comes from the USAMU, which provide shooting and reloading tips on its Facebook Page. This week’s USAMU TECH TIP outlines a ballpark-estimate method of calculating the actual cost per round of different calibers. Some applications, and some shooters, by virtue of their high level of competition, require the very best ballistic performance available — “Darn the cost, full speed ahead!
If you are in serious contention to win a major competition, then losing even a single point to inferior ballistic performance could cost you a national title or record. However, this “horsepower” does come at a cost! Some calibers are barrel-burners, and some offer much longer barrel life. Look at this comparison chart:
Estimated Cost Per Round by Cartridge Type
Below are some estimated total expense per round (practice and competition) based on component costs, type used, expected barrel life and a standard, chambered barrel cost of $520.00 across calibers.
5.56x45mm: $0.46/round (barrel life 6,000 rounds)*
6mmBR: $0.81/round (barrel life 2800 rounds)
6XC: $0.97/round (barrel life 2200 rounds)
.308 Win: $0.80/round (barrel life 4500 rounds)
6.5-284: $1.24/round (barrel life 1100 rounds)
*Note the high round count estimate for 5.56x45mm. This is a bit deceptive, as it assumes a period of “lesser accuracy” use. The USAMU says: “Much of the difference you see here between 5.56 and .308 is due to using the 5.56 barrel for 100-200 yard training with less-expensive, 55gr Varmint bullets after its long-range utility is spent”.
Moreover, while some applications require specialized, high-cost components, others do not. And, if the shooter is still relatively new to the sport and hasn’t refined his skill to within the top few percentile of marksmen, a more economical caliber choice can help stretch a limited budget. Translation: More skill per dollar!
In this post, the prices for all items mentioned here were taken from a major component supplier’s current advertisements, and all brass was of top quality, except in the case of 5.56mm. There, 200 top-quality, imported cases were reserved for 600-yard shooting, and the other brass used was once-fired Lake City surplus.
Cartridge cases were assumed to be loaded 10 times each. [Your mileage may vary…] Bullet prices assumed the use of less-expensive, but good-quality match bullets for the bulk of shooting as appropriate.
The cost of top-tier, highly-expensive match bullets was also calculated for a realistic percentage of the shots fired, based on ones’ application. Barrel life by caliber was taken from likely estimates based on experience and good barrel maintenance.
Brass Costs Based on 10 Loads Per Case
Often, handloaders may calculate ammunition cost per round by adding the individual costs of primers, powder charges and projectiles. Many don’t consider the cost of brass, as it is reloaded several times. Here, we’ll consider the cost of enough top-quality brass to wear out a barrel in our given caliber, at 10 loads per case, except as noted above.
Don’t Forget Amortized Barrel Costs
Few shooters factor in the full, true cost of barrel life. Depending on caliber, that can dramatically increase the cost per round. For example, consider a long-range rifle in 6.5/284 caliber. This cartridge performs amazingly well, but at a cost. Ballpark estimated barrel life [in a top-quality barrel] is 1100 rounds. Some wear out faster, some last longer, but this gives a rough idea of what to expect.
Accurate barrels are a joy to use, but they are an expendable resource!
A top-quality barrel plus installation was estimated at about $520.00. At 1100 rounds, barrel life adds $0.47 per round to our total cost. Thus, what had started out as an [components-only estimate, with brass cost] of $0.76/round now totals $1.24 per shot!
Cost Considerations When Choosing a Catridge Type
Some shooters might ask themselves if they could meet their present needs with a more economical caliber. If so, that equates to more practice and matches per available dollar, and more potential skill increase on the available budget.
Each shooter knows his skill level, practice needs, and shooting discipline’s requirements. Some might shoot NRA Service Rifle or Match Rifle using a 5.56mm with a long barrel life. Others might be Match Rifle shooters faced with choosing between, say, a 6mm BR vs. 6XC. A realistic assessment of ones needs, performance-wise, may help guide the shooter toward a caliber that’s most optimized to their needs at the moment.
Admittedly, the factors affecting cost for any individuals circumstances can vary significantly. However, hopefully this will provide one useful method of evaluating one’s training and competition choices, based on their skill, goals and needs.
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Here’s something you don’t see very often — Lapua cartridge brass on sale. As part of its Back-to-Black promotion, Brownells has deeply discounted its inventories of Lapua Brass. For most cartridges/calibers, the price has been reduced at least $10.00 per 100-count box. Here are the sale prices, good through the end of the week:
Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion.
Cartridge Efficiency: A Primer (pun intended!)by USAMU Staff
Each week, the U.S. Army Marksmanship Unit (USAMU) publishes a reloading article on its Facebook Page. In this week’s article, the USAMU discusses cartridge case efficiency and its benefits. While this is oriented primarily toward NRA High Power Rifle and Long Range (1000-yard) competition, these factors also apply to medium/big game hunters. Assuming one’s rifle and ammunition are accurate, key considerations include ballistic performance (i.e., resistance to wind effects, plus trajectory), recoil, and throat erosion/barrel life.
Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion. A classic example in the author’s experience involved a featherweight 7x57mm hunting/silhouette rifle. When loaded to modern-rifle pressures, just 43-44 grains of powder pushed a 139gr bullet at 2900 fps from its 22” barrel. Recoil in this light rifle was mild; it was very easy to shoot well, and its performance was superb.
An acquaintance chose a “do everything” 7mm Remington Magnum for use on medium game at short ranges. A larger, heavier rifle, it used ~65 grains of powder to achieve ~3200 fps with similar bullets — from its 26″ barrel. Recoil was higher, and he was sensitive to it, which hampered his shooting ability.
Similarly efficient calibers include the 6mm BR [Norma], and others. Today’s highly-efficient calibers, such as 6mm BR and a host of newer developments might use 28-30 grains of powder to launch a 105-107gr match bullet at speeds approaching the .243 Winchester. The .243 Win needs 40-45 grain charges at the same velocity.
Champion-level Long Range shooters need every ballistic edge feasible. They compete at a level where 1″ more or less drift in a wind change could make the difference between winning and losing. Shooters recognized this early on — the then-new .300 H&H Magnum quickly supplanted the .30-06 at the Wimbledon winner’s circle in the early days.
The .300 Winchester Magnum became popular, but its 190-220gr bullets had their work cut out for them once the 6.5-284 and its streamlined 140-142gr bullets arrived on the scene. The 6.5-284 gives superb accuracy and wind performance with about half the recoil of the big .30 magnums – albeit it is a known barrel-burner.
Currently, the 7mm Remington Short Action Ultra-Magnum (aka 7mm RSAUM), is giving stellar accuracy with cutting-edge, ~180 grain bullets, powder charges in the mid-50 grain range and velocities about 2800+ fps in long barrels. Beyond pure efficiency, the RSAUM’s modern, “short and fat” design helps ensure fine accuracy relative to older, longer cartridge designs of similar performance.
Recent design advances are yielding bullets with here-to-fore unheard-of ballistic efficiency; depending on the cartridge, they can make or break ones decision. Ballistic coefficients (“BC” — a numerical expression of a bullet’s ballistic efficiency) are soaring to new heights, and there are many exciting new avenues to explore.
The ideal choice [involves a careful] balancing act between bullet BCs, case capacity, velocity, barrel life, and recoil. But, as with new-car decisions, choosing can be half the fun!
Factors to Consider When Evaluating Cartridges
For competitive shooters… pristine accuracy and ballistic performance in the wind are critical. Flat trajectory benefits the hunter who may shoot at long, unknown distances (nowadays, range-finders help). However, this is of much less importance to competitors firing at known distances.
Recoil is an issue, particularly when one fires long strings during competition, and/or multiple strings in a day. Its effects are cumulative; cartridges with medium/heavy recoil can lead to shooter fatigue, disturbance of the shooting position and lower scores.
For hunters, who may only fire a few shots a year, recoil that does not induce flinching during sight-in, practice and hunting is a deciding factor. Depending on their game and ranges, etc., they may accept more recoil than the high-volume High Power or Long Range competitor.
Likewise, throat erosion/barrel life is important to competitive shooters, who fire thousands of rounds in practice and matches, vs. the medium/big game hunter. A cartridge that performs well ballistically with great accuracy, has long barrel life and low recoil is the competitive shooter’s ideal. For the hunter, other factors may weigh more heavily.
Cartridge Efficiency and Energy — Another Perspective
Lapua staffer Kevin Thomas explains that efficiency can be evaluated in terms of energy:
“Cartridge efficiency is pretty straight forward — energy in vs. energy out. Most modern single-based propellants run around 178-215 ft/lbs of energy per grain. These figures give the energy potential that you’re loading into the rifle. The resulting kinetic energy transferred to the bullet will give you the efficiency of the round. Most cases operate at around 20-25% efficiency. This is just another way to evaluate the potential of a given cartridge. There’s a big difference between this and simply looking at max velocities produced by various cartridges.”
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Jonathan Ocab, a High Power shooter from California, had gunsmith Doan Trevor install a Sako-style extractor in the Rem 700 bolt in Ocab’s 6mmBR Eliseo R5 tubegun. Jonathan produced an excellent video showing how the Sako extractor improves the ejection of the short, fat 6mmBR cartridges in his rifle. Jonathan’s video demonstrates 6mmBR case ejection with an unmodified Rem 700 factory bolt versus a factory bolt fitted with a Sako-style extractor.
Johnathan explains: “Note how even when slowly operating the bolt, the bolt with the Sako extractor easily ‘kicks’ out the brass on ejection with minimal chance of operator error resulting in a failure to extract. While the unmodified bolt has issues ejecting brass on slow operation, it will eject if the operator pulls the bolt back quickly (fast and with some force).
While a Sako-style extractor isn’t an absolute necessity, this video shows the definite improvement this modification provides. For short cartridges like the 6mmBR, this is very useful. This modification is highly recommended for competition shooters, especially High Power competitors who seek improved function in rapid-fire stages. This modification is fairly inexpensive and any competent gunsmith should be able to perform the work (usually under $100 with parts and labor).”
EDITOR’s NOTE: In his video, Jonathan deliberately worked the unmodified Remington bolt slowly to show how the standard Rem extractor can struggle with short fat cases like the 6mmBR. In fact, when you work a standard, unmodified bolt more quickly, the extraction can be much more positive. Cycling the bolt with more “snap” provides more energy to eject the cases. We have run an R5 Tubegun chambered in 6mmBR with an unmodified Rem 700 bolt (no SAKO extractor), and the extraction was reliable, provided the bolt was worked quickly.
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Made with Lapua’s typical dedication to precision, our new 6.5 Creedmoor case has been refined just a bit, to make it an even better performer. We’ve opted for the small rifle primer, which normally produces an optimized ignition and better accuracy than large primers in mid-sized cartridges like the Creedmoor.
Many visitors to the site ask us, “I’ve got a .223 and .308. What will a 6mmBR Norma (6BR) give me that I’m not getting already?” Well first you will probably average consistently smaller groups than your current .223 or .308 rifle (assuming the 6BR has a quality barrel and trigger). A good .308 Winchester can be superbly accurate, no question about that, but the lesser recoil of the 6BR works in the shooter’s favor over a long string of fire. Even with a Rem 700 or Savage action factory action, a 6BR with a benchrest stock, premium barrel, and a high-quality chambering job should deliver 5-shot groups in the high twos to mid-threes, provided you do your job. We have one 6BR rifle that shoots Lapua factory-loaded 6BR ammunition in the low twos and high ones. That’s exceptional, we admit, but it still shows how the 6BR is an inherently accurate cartridge, even with factory loads.
Forum member Al Nyhus is a top-level score shooter who has competed successfully with the 
How well can the 6mm Dasher perform at 1000 yards when conditions are good, and the shooter is riding a hot streak? Well here’s a shot-by-shot record of Scott Nix’s 4.554″ 10-shot group shot at Missoula, Montana at the Northwest 1000-yard Championship a few years back. All 10 shots were centered for a 100-6X score. That’s about as good as it gets. If Scott had stopped after 5 shots, his group would have been under 3 inches!
In our 
