600-Yard World Record Light Gun
David Stripling Sets IBS Record 1.071" Group with 6BR-DX
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Last July, North Carolina's David Stripling, a relative newcomer to the long-range BR game, posted a stunning 1.071" 5-shot group at one of Piedmont's 600-yard IBS matches. Officially approved just this week, David's new Light Gun record cuts about 0.29" off the previous IBS LG record (1.363" by Greg Cullpepper). And get this, David posted a 2.590" 20-shot Agg, despite having one mid-4" group. David's 6BR-DX rifle, smithed by Doug Paschall, (336) 731-4618, features a 10-twist, 25" Krieger barrel. Notably, David set the new mark using flat-based 88gr Berger bullets pushed by a very stout load of Reloader 15. We give credit to David and Doug for "pushing the envelope" at 600 yards--not just copying the same old 107 SMK + Varget formula. Click to see David's World-Record Target, signed, sealed and delivered.
Photo shows Leupold 8-25x50 LRT boosted to 20-50x by Premier Reticles. Note the extra section of tubing behind the zoom ring.
Perspectives on the 600-Yard Game by David Stripling
First let me say I don't have years and years of long-range benchrest experience, so I'm not going to hold myself out, in this article, as some kind of "expert". I'm not going to preach about the "best" way to shoot free-recoil, or gauge mirage, or achieve .0005" run-out on your cases. What I can do is explain how, with the right components, and a good smith, even a new guy can have his moment of glory, and maybe even set a World Record in the process.
To be very honest, I feel fortunate to have shot so well at Piedmont, but I credit much of that success to my equipment and Doug Paschall's mentoring. The lesson to be learned from my 2005 performance is that, with the right gear, and attention to details, even a guy without decades of experience can do well in the 600-yard benchrest game. Especially if you have a cartridge with the performance and inherent accuracy of Doug's 6BR-DX.
The Evolution of the Record Rifle
This wasn't a situation where I set out to build a no-holds-barred record-breaker, without concern for cost. The gun had somewhat humble origins. This rifle was originally built for fun groundhog shoots and shooting live varmints. It was initially stocked in a Kelbly HBR stock. After shooting several matches I decided to restock it in a 3"-wide stock for more stability. The S.G. & Y. BRX stocks looked like they were very well-designed and nicely crafted. So, I ordered one and have been very pleased. The stock tracks very well and it is very light. The Robertson Composites-made BRX stocks are finished extremely well.
The action on this gun is a Nesika Model K right bolt / left port with a 1.350" diameter body. We customized the bolt-handle a little, with a knob tricked out like a muzzle brake. The action is fitted in one of Speedy's BRX stocks with Robertson Composites' signature marbled finish, in black and a medium gray. Scope is a Leupold LRT, fitted in Kelbly 30mm rings. Originally an 8-25x, Premier Reticles boosted the scope to 20-50x power. I like the scope very much, it is sharp, and it is nice to be able to dial up some serious magnification when you're trying to see bullet holes at 500 or 600 yards. Trigger is a 1.5 oz Jewell, and Doug fitted a Vais muzzle brake. The brake works great, but in hindsight, I sometimes wish I'd taken it off at Piedmont so I could have shot the Heavy Gun relay when Terry Brady shot a superb score with his Heavy Gun. That was earlier in the morning, and conditions were nearly perfect. (Editor's Note: The same day David shot his record LG group, Terry ended up with a World Record 403-14X HG/LG Score Agg. The next month, at Piedmont, Terry shot a .860" World Record HG group.)
The polished Nesika is mated to a 25" Krieger (1:10", 4-groove). I bet some readers are surprised by that length. 25" is "stubby" by the standards of many 600-yard shooters. Well, with the lighter bullets and slower twist, you don't need a 28" or longer barrel. I went with a 4-groove Krieger because Doug Paschall, my gunsmith, had very good luck with this combination on another 6BR in the past so I trusted his advice.
|6BR-DX--Ackleyized 6BR with Full Neck|
The first time we saw a close-up picture of the 6BR-DX we said, "Wow, that looks just about perfect for 500 and 600 yards." It looked like the case might be the best of both worlds for benchrest's "middle game", i.e. from 300 to 600 yards. The extra case capacity gets you up into into a nice velocity node that delivers both extreme accuracy and wind-cheating ballistics. Yet, the neck is not shortened much at all so fire-forming is simple and you have lots of flexibility with seating depths and bullet types.
This is a cool new cartridge with lots of potential. The Ackleyized BR case looks like a Dasher, but with a long neck. It has 40° shoulder and a bit less body taper than a Dasher. With the extra boiler room provided by the 40° shoulder (and slightly reduced body taper), David can stuff 34+ grains of RL15 into the 6BR-DX, even though the neck, at 0.283", is just .039" shorter than a standard BR. With the added capacity, David can launch Berger 88s at nearly 3300 fps, or Berger 95s at 3200 fps. And, in case you're wondering, at that speed, David says "the 95s stabilize just fine in my 10-twist Krieger." Though he is "ecstatic" with the cartridge's performance with 88s, when the barrel wears out, David plans to try a 9-twist as well with some heavier bullets. We think we will be seeing more of this cartridge in the months ahead.
The 6BR-DX--Specs and Load Development
The 6BR-DX is an improved version of the 6mm BR Norma cartridge, with a 40° shoulder. The shoulder is .462" (just a couple thousandths bigger than a standard case) and the diameter at the web is .470". 6BR-DX water capacity is about 39.5 grains. That's about 1.5-2.0 grains more than a standard 6BR case, depending on your chamber. That extra two grains is enough to give the case performance nearly on a par with the 6mm Dasher or 6 BRX, with the 85-95 grain bullets. This case will drive those pills plenty fast. I'm able to run the Berger 95s at 3200 fps, pretty much as fast as you can push them with a Dasher.
But compared with a short-necked Dasher, fire-forming the 6BR-DX is much easier. It's very simple in fact. After turning the necks to .262", we simply load the cases with a good "full-power" load for a standard 6BR and fire. Creating a false shoulder or doing other tricks is not necessary. My 6BR-DX dies are made from a Redding competition set. These have inner sleeves which can be reemed. Doug ran the chamber reamer in both the sizing die and the neck die. We did find that, after 5-6 firings with the hottest loads, bolt lift was getting a bit stiff, so we needed to bump the shoulders back a bit. Doug got a Newlon die blank and Dave Kiff (Pacific Tool & Gauge), provided a reamer slightly smaller than the chambering reamer. With this, Doug created a full-length sizing die that just resizes the body a bit, and bumps the shoulder. It's fitted with bushings to size the neck as well. I don't need to use the custom FL die every time, but when extraction gets a little hard, I'll run the cases up in that die and bump the shoulders a tad. If you build a 6BR-DX, you'll definitely want a similar die for full-length sizing. Just have your gunsmith call Dave Kiff and ask for a copy of Doug Paschall's die-cutting reamer.
I tried a variety of powders in the 6BR-DX including Varget and IMR 4895 borrowing some suggested loads for both the Dasher and BRX. Among the popular powders, Alliant Reloader 15 seemed to work the best in my rifle--providing an impressive combination of velocity and accuracy. With the RL15, I tried the Berger 80gr match, 88gr Low-Drag match, and the Berger 95 VLD bullets. While the 95s performed well, in my 10-twist barrel, it really liked the 88s. The rifle shoots the best with a near-max load of RL15 pushing the 88-grainers at around 3300 fps. (Editor's Note: Berger claims a .395 BC for the 88s. If you run the ballistics for the 88s at 3300 fps, you'll see they compare favorably with 107gr SMKs going 2885 fps. The 107s drift less in a cross-wind, but the 88s shoot flatter, and have a shorter time of flight. See Chart.)
|Velocity||Drop at 600 yards||Drift at 600 yards|
10mph 90° Crosswind
|Berger 88 LD||0.395||3300 fps||81.42"||27.84"||0.704 sec|
|Sierra 107 MK||0.527||2885 fps||97.89"||23.64"||0.758 sec|
Calculated with PointBlank Ballistics program for 500' Altitude, 70° temp.
How It Feels to Set a Record
I set my record on July 23, 2005 at Piedmont on my fourth relay. Other records were set that day, so conditions were obviously good. (Editors Note: Terry Brady set a HG/LG Score Agg record and Mark Schronce set a new HG Record Score Agg of 203-8X.) Things were very still in the early morning then the winds came up a bit. But I had been shooting well in the three previous relays, so I seemed to have a pretty good feel for the winds. When shooting the 1.071" record, I did NOT send them down range as fast as I could. I waited on the wind flags on EVERY shot, waited for my condition to return. The gun was handling well, and I felt that I had shot well, but I had NO idea those five shots had gone into an inch (or even close to an inch!). When I heard people saying someone shot a record group on the last relay, I certainly did not think I had done so. I figured it must have been one of the other guys. But Joel Kendrick came over and congratulated me. It was pretty amazing. I had a real sense of accomplishment at having shot that well at 600 yards. I hope to never forget that good feeling.
Can I shoot another record? Who knows? I'll certainly try, but 600-yard matches are very competitive. On "any given weekend" there are a bunch of great shooters at Piedmont that can win the match. Unlike short-range benchrest, no single cartridge (or caliber) dominates competition. You'll see many different calibers on the firing line of 600-yard matches. There are 6mms, 6.5s and 30s and they can all shoot well. Records were falling every month. But I hope, with another good barrel, I'll be back in the running in 2006. I won't be moving to an 8-twist to shoot heavier bullets. I've had real good results with the 10-twist (and 85-95 grain bullets) so I'm sticking with that. Also I will stick with Krieger, that much is for sure.
|Doug Paschall Talks about his 6BR-DX|
David Stripling's close friend and gunsmith Doug Paschall dreamed up the 6BR-DX after many seasons of tinkering. Doug analyzed the strengths and weaknesses of the other 6BR Improved cases, such as the Dasher and BRX. Doug wanted a bit more capacity than the standard case allowed and he wanted the advantages of an Ackley Improved shoulder, but he did not want to sacrifice too much neck length. Doug believes the 6BR's long neck contributes to accuracy, barrel life, and gives it greater flexibility in shooting a wide range of bullet weights. Doug has always been an innovator and something of an independent thinker. Doug noted the success of 6BRs shooting 105s and 107s through 1:8" twist barrels at 500 and 600 yards. However, he felt that the potential of somewhat lighter bullets, propelled at 3150+ fps velocities, was still untapped. Hence he designed David's gun and fitted it with a 1:10" twist barrel to shoot Berger 88gr Low-Drag flat-based bullets and Berger 95gr VLDs.
Doug tells us: "The 6BR-DX was created over time with a good deal of trial and error. I'm now 68 years young, but slowing down to shoot more and work lots less. It was nice to see that, after so many years working on guns, we've really hit on something remarkable with this BR-DX. The 6BR first caught my eye in late 1983. It seemed like an almost ideal case for the Egg Shoots and 500-yard groundhog matches that were becoming popular. Then about 1993 I bought a Remington 40X BR. That was much fun, let me tell you. I found it shot the light bullets very well. At 500-yard groundhog targets it could deliver 1.5" groups with lightweight bullets, but it was VERY wind-sensitive.
I wanted a round that would buck the wind better, which meant longer bullets, but I didn't want to sacrifice too much velocity. I wanted a case with a couple grains more capacity, and I liked the 40-degree shoulders I saw on the Dashers. The full 40-degree Ackley Improved shoulder provides very stable brass once it's fire-formed. With a little more dreaming and tinkering, I came up with the 6BR-DX. It gave me a couple grains more capacity, while still retaining most of the neck. If you compare the case with a BRX, you'll see the 6BR-DX neck is quite a bit longer. I came up with three different test versions, and JGS ground the first three reamers. All versions performed great, but the third produced the heavy bullet (95-107 grain) velocity I was looking for.
So far, we've had good success with the BR-DX in a variety of barrels--Krieger, Hart, Spencer, Shilen. After testing many, many different bullet types, I settled on Berger for long-range competition. The Low-Drag 88-grainers work primo in 10-twist and 9-twist barrels, as do the 95 VLDs. I know some knowledgeable guys who say you can't shoot the Berger 95gr VLDs from a 10-twist barrel. I respect their views, so I don't want to argue the point. But I've found, at the velocities we're getting, in the barrels we've tried, the 95s stabilize fine from a 10-twist out to 600 yards. Our targets and match results prove it. But certainly, if you want to play it safe, go with a 9-twist for the 95 VLDs. I used a 9-twist Krieger to win the 2005 NC State Champs with my BR-DX. I want to add that you can still shoot the lighter bullets even in a 9- or 10-twist. The 9- and 10-twist will shoot the gee wiz out of light bullets.
6BR-DX Shines in Competition
In 2005, David Stripling and I campaigned the "DX" at Piedmont Gun Club in Rutherfordton, North Carolina. Piedmont is a great venue. The Club runs a very well-organized, IBS-sanctioned 600-yard match that draws many top shooters. How did we do with our 6BR-DX? Well, they knew we there every month that's for sure.
On June 25, 2005, I won Light Gun Group with a 2.888" Agg. On July 23, at David's second match, using Berger 88s, he set his World Record 1.071" five-shot group. In September, I won the North Carolina State Championship with First Place in Group, Score, and Aggregate. At that match I shot Berger 95s with a Krieger 9-twist.
If those kind of results appeal to you, I suggest you join the fun and try a 6BR-DX. I have authorized the following toolmakers to produce 6BR-DX reamers: JGS, Pacific Tool & Gauge (Dave Kiff), and Hugh Henriksen. While I'm pretty busy with projects now, if you have questions about the cartridge and load tuning that aren't answered in this article, you can email Mailbox@6mmBR.com and your editor can forward them to me. Best of luck to you all." —Doug Paschall
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