Beginski’s New 6mm-6.5×47 Lapua
3-Way Velocity Challenge: 6BR vs. 6BRX vs. 6-6.5x47 Lapua
There has been much interest in a necked-down variant of the new 6.5×47 Lapua cartridge. Joel Kendrick, at the recent IBS 600-yard Nationals, won the Two-Gun Overall Championship with a 6mm version of the 6.5×47, formed down to 6×44. Robert Whitley has created another 6-6.5×47 wildcat, optimized for Highpower competition, which he calls the 6mmHOT.
As supplies of 6.5×47 brass have just arrived recently, load data for a 6mm wildcat version is still hard to find. However, Washington state gunsmith Rick Beginski has already built four 6-6.5×47 rifles using a .268″ neck design. He was kind enough to provide AccurateShooter.com with this early report on his results with the cartridge. To give a solid baseline on the velocity potential of the new cartridge, Rick tried three different chamberings on two of his benchrest guns. On each gun, its barrel was first chambered as a 6BR, then as a 6BRX, and finally as a 6-6.5×47. This way everything was held constant, other than the chambering. Rick’s testing therefore shows how much added velocity you can attribute to the chambering alone. Rick reports: “So far, so good. Going from a 6mmBR to a 6-6.5×47 will give you an extra 200 fps easy, and that’s very conservative I’d say.” Once his barrels were completed as 6-6.5x47s, Rick was able to get good velocities and good accuracy with a variety of powders. And now that Forster Products is shipping a quality full-length sizing die for the 6-6.5×47, we think this wildcat will become very popular in the months ahead.
A New Wildcat–The 6-6.5×47 by Rick Beginski
Testing Velocity and Accuracy with Three Chamberings (6BR, 6BRX, 6-6.5×47)
I hope this helps somebody getting started with a project using the Lapua 6.5×47 case necked down to 6mm. For convenience, I’ll call this a 6-6.5×47 in this article (not to be confused with the older 6×47 based on a 222 magnum). The purpose of this test was to find out just how much faster one can make a 105-107 bullet go with the new 6.5×47 Lapua case versus a 6BR or 6BRX. I wanted the results to be rock solid. However, recognizing that different barrels may vary up to 100 fps in maximum velocity, I felt there could be a problem if I used different actions/barrels for the different chamberings. You might get a really fast 6mm barrel for one chambering and a really slow barrel on another. Therefore I decided to test all three chamberings in the same barrel. And, to make things even more interesting, I repeated the triple-chamber test in a second rifle (so that’s a total of 6 chambering jobs, three in each rifle.)
One Barrel–Chambered Three Ways
I wanted to see actual velocity results from the same barrel, so I chambered two rifles in three steps, first as a 6mmBR, second as a 6BRX (a 6BR improved with 30° shoulder), and lastly as a 6mm-6.5×47. I already owned 6BR and 6BRX reamers, but I needed new chambering tools for the 6-6.5×47 since the cartridge is so new, and the 6mm version is still in its wildcat stage.
I ordered a 6-6.5×47 Lapua finish chamber reamer from Pacific Tool and Gauge. A case with a bullet seated measures .2695″. I wanted to get a good clean-up on the necks so the neck was made .268″ on the finish reamer. I also ordered a resize reamer from PT&G with a .263″ neck–this was used to make a custom, forming/full-length sizing die. The next thing was to ream a set of Wilson dies for neck sizing and seating. Another option now is to buy a Forster die set from Graf and Sons (Grafs.com has them in stock). The Forster full-length die sizes both the web and shoulder down about .001″ from fired dimensions, but keep in mind it only takes the neck down to .266″, so you’ll need some way to size the neck a bit more if you turn your cases below .268″ loaded diameter. (Editor’s NOTE: the neck diameter of the die is .267″ according to Forster.)
|Velocity and Accuracy Testing (Three Chamberings)|
For my 6BR to 6BRX to 6-6.5×47 Lapua test, I tried to keep the test components very similar. The test rifles both use Tooley MBR stocks, and they both have Krieger barrels (one is a used 26″ barrel with about 600 rounds, the second is a new 30 incher). Both rifles are built with blue-printed Remington actions, one a 40X and the other a sleeved XP100.
Phase ONE: 6BR
I initially chambered both rifles as 6BRs, to get a velocity baseline with the smallest cartridge. Using a relatively “standard load” of 30.0gr of Varget, the 26″ barrel averaged 2811 fps while the 30″ barrel delivered 2839 fps. I think you can attribute most of the velocity difference to the extra length. [Editor’s Note: During Jackie Schmidt’s 6BR Railgun test, we cut down a Krieger barrel from 33″ to 28″. The speed differential was 40 fps–with the velocity change very uniform at about 8 fps per inch of barrel length.] Note, I could have pushed these loads higher, but I wanted to use a fairly standard load that many guys are using in their 6BRs.
Phase TWO: 6 BRX
For the second part of the test, I replaced the 6BR chamber with an “improved” version. Both barrels were made into 6 BRXs. This time I choose H4895, which has proven very accurate in many of the BRX rifles I’ve built for clients. The test load was 32.5gr of H4895. In the 26″ barrel, this load ran 2956 fps, while in the 30-incher it gave 3017 fps.
Phase THREE: 6-6.5×47 Struts Its Stuff
Now it was time to see what the 6-6.5×47 could do. I removed both barrels, set them up and reamed each of them one more time to 6-6.5×47. Then we headed to the range. Both accuracy and velocity were good. I tested seven different powders. In order of burn rate (fastest first): VV N-140, Reloder 15, VV N-550, Reloder 19, H4350, VV N160, and H4831sc. There is no question the bigger case will drive 105-107 grain bullets quite a bit faster than a 6mm Dasher or BRX–and at lower pressures. Mid-3000s were not a problem with pretty much any powder, and (in a later test), I was able to get 3120 fps with BIB 108-grainers. Here is a chart showing 6-6.5×47 velocities, and corresponding powder loads:
|6-6.5×47 Load Data and Velocities for 105-107gr Bullets|
|Powder||2900 fps||2960 fps||3000 fps||3030 fps||3050 fps||3080 fps||3120 fps|
|NOTE: this data is not a recommendation, it’s just what worked in these test rifles. Always start 10% low and work up.|
NOTE: All of the velocities in the load data table are from the 30″ barrel. On average, the 26″ barrel ran about 60 fps behind the longer barrel. In both barrels, the most accurate load was 35.7gr of VV N-550. Second best was 40.3gr of H4350. I’d like to do more testing with H4350. It put five, 5-shot groups in the 2s and 3s at 100 yards (see target below), and it was a little faster than the N-550 load. [Editor’s NOTE: Rick was pretty conservative in his H4350 loads. We’ve received reports from shooters that have tried up to 41.0 grains H4350 with 105s in a 6-6.5×47. Accuracy was excellent and speeds topped 3150 fps.]
Experiment with a Nine-Twist
As an experiment, I put together a third 6-6.5×47 rifle using a 9-twist Hart barrel. I was interested to see whether the 9-twist would work with the higher velocities this case can deliver (compared to a 6BR). I think the 9-twist is a viable option with some of the 100+ grain bullets. I learned this rifle really likes the 108-grain BIB flatbase bullets. The only powder I tried with the 9-twist rifle was H4831sc. With this barrel I could get to 3120fps with 41.0gr of H4831sc but it shot the best at the 38.6 load. More testing is in order for this one.
Rifle #4–a Lighter-Recoiling Deer Rifle to Replace a .270
I think the 6.5×47 case has a lot of potential as a hunting round. In a 6mm version, it will deliver performance very similar to a .243 Win, but with less powder, and the ability to mag-feed even with very long bullets. I recently built up a 6-6.5×47 hunting rifle for a 78-year-old friend who says his .270 is starting to kick too much. Shown in the picture below, this is a trued 722 Remington with extended bolt handle. The action is bedded in a Boyds stock, reworked for the BDL hinged floor plate and magazine. One good thing about this combo is that loaded rounds fit down in the magazine with bullets seated to the same COAL as the benchrest rifles so you don’t have to change your seating die settings. For owners of 6-6.5×47 competition rifles, building a hunter like this makes a lot of sense. Having a like-chambered hunting gun gives you a place to use your sorted-out brass, and I don’t think the coyotes will ever know this wasn’t your best ammo.
CONCLUSION: A Practical Wildcat with Great Potential
Is this a new wonder round? Maybe not, but it does give you about 200 fps over a 6BR with off the shelf Lapua brass that you don’t have spend time forming from some other caliber. There are lots of wildcat rounds that do the same thing and even some factory rounds that will work, but this gives you factory brass and dies to work with, in a well-balanced round. – Rick Beginski
As soon as the 6.5×47 Lapua brass arrived in the USA, Robert Whitley started working on a 6mm wildcat version. Robert explained: “While many feel a 6.5mm cartridge has merit, many also see this cartridge, in a 6mm version, as fulfilling a long desired need for a cartridge that has inherently more ‘horsepower’ and a larger case capacity than the 6mmBR, the 6mm Dasher, the 6mm BRX, etc. The case is very close in size and performance to a 6XC. The quality of the Lapua brass is unbelievable, and it has a small primer pocket and a small flash hole, which makes it even better. From a lot of perspectives, this brass is an ideal high pressure vessel that helps to make this 6mm cartridge a fast hot cartridge.” In putting together his “6mmHOT” version of the cartridge, Robert has worked with Dave Kiff to create reamers optimized for no-turn brass with ample neck clearance–designed for cross-course and prone rifles. Thus far, Whitley’s pioneering work has gone very well. Here are some of his initial findings:
Basic Load Information
Top end (maximum) loadings will vary depending on the rifle, barrel, lot of powder, etc.; every gun is different. But “practical max” loadings with the 105-107gr bullets are being reported in the range of 38-42 grains of H4350. One report indicated a shooter using 41.0+ gr of H4350 with Berger 105 VLD’s and achieving 3210-3230 fps with stellar accuracy, and without pressure issues. [Editor’s NOTE: Forum Member ‘Reverend’ achieved 3250 fps with Lapua Scenar 105s using a 41.0 grains of H4350 in a 30″ Schneider P5 (polygon) barrel. Note this was substantially higher than the velocity Rick Beginski could achieve in any of his four rifles. The polygon rifling may make a difference. Realistically, 3150 fps may be the top end in most barrels using H4350.]
Initial Testing with H4350 in a Tube Gun
35.9gr H4350 + Sierra 107 MatchKing (.010″ jump) = 2808 average velocity, ES 36, SD 14
With new, necked-down brass, the extreme spreads and standard deviation numbers are generally a little higher than if previously-fired brass was used. In addition, the Lapua brass, at 39.0gr of H4350, was still showing no pressure signs or issues, and it appears, in the rifle used, the load could be boosted higher.
The Vihtavuori Solution–Whitley Has Great Luck with N160
The target on the left was shot on August 13, 2006 with the author’s Highpower rifle (the same rifle noted in the chrono tests). The target was shot prone with a sling at 100 yards, and represents 10 shots. The load was 38.2gr of N160 with a Remington 7 1/2 BR primer and Berger 105 VLD bullets loaded .010″ into the lands. At around 2950 fps, this has promise to be a great 600-yard Highpower rifle loading, especially since there were no pressure signs. The disbursement of the group is mostly from the pulse and body movement of the author, while shooting unsupported and prone with a sling. The rifle, with this load, seemed as if it wanted to put the bullets all through the same hole if the author could hold still enough to do it.” – Robert Whitley, (215) 348-8789.
Whitley’s 6mmHOT Reamer Design (PT&G #9206)
Note: The reamer below was set up for Highpower rifle competition as a “no neck turn” reamer with .005″ neck clearance over a loaded round (i.e. non-neck turned loaded rounds measure right around .270″ at the neck). If you wish to neck turn and have special reamer requirements feel free to call Dave Kiff at Pacific Tool and Gauge to set up a reamer to your requirements.
6mmHOT information Copyright © Robert Whitley, All Rights Reserved, used by permission.
No reproduction of any content without advanced permission in writing.
Topics: Rick Beginski, Washington, Hart, Krieger, Vihtavuori, Hodgdon, Reloader, Reloder 15, Reloder 19, H4350, H4831, H4931sc, N550, N160, Lapua, 6.5×47, 6,5×47, 6.5-47, Finland, Darrell Jones, Heavy Gun, Light Gun, Remington, XP100, Actions, Robert Whitley, 6mmhot.com, 6mm HOT, Krieger Barrels, Tooley MBR, Rutland Laminate, Laminated, 6.5mm, 6×47, brass, Sierra Bullets, SMK, Berger, Cauterucio, F-Class, 600 yards, 1K, IBS, NBRSA, 300m, 800m, Varmint, Varminting, Jewell trigger, Benchrest, BR, Bench Rest, Single-shot, competition, rifle accuracy, Alliant, Rem 7 1/2, 7.5, CCI BR4, CCI 450, CCI primers, Alliant, Berger, Dave Kiff, Pacific Tool & Gauge, Pacific Tool and Gauge, Lathe, stocks, Weaver, Wilson Die.