February 11th, 2018

Berger SW Nationals 2018 — Hail the Champions

Berger SW Nationals Ben Avery Wind

Today was the final day of the Berger Southwest Nationals (SWN). Two 1000-yard individual matches were scheduled. But the weather gods did not cooperate. Sunday matches were cancelled due to high, gusty winds from the North-Northeast that made it very difficult to handle the large, wood target frames. With concern for the safety of pit workers, match organizers waited until 10:00 am, then canceled the matches. It was a disappointment for some, but all the competitors still enjoyed a great week at Ben Avery.

With the cancellation of Sunday matches, the three individual champions — Sling Division, F-TR, and F-Open have been decided based on the Friday and Saturday results. We congratulate the three new Champions: Bob Sebold (F-Open), Phillip Kelley Jr. (F-TR), and Allen Thomas (Sling).

Top Five Overall – F-Open
Bob Sebold, 843-49X
Keith Glasscock, 843-38X
Jay Christopherson, 841-45X
Stephen Potter, 841-37X
James Crofts, 841-34X
Top Five Overall – F-TR
Phillip Kelley Jr., 838-35X
Ellis Berry, 837-42X
Niklas Montin, 836-35X
Peter Johns, 835-36X
Edward Shelley, 832-33X
Top Five Overall – Sling
Allen Thomas, 844-37X
Oliver Milanovic, 843-45X
Trudie Fay, 842-32X
Nancy Tompkins, 840-43X
Angus McLeod, 840-43X

Team matches concluded yesterday, Saturday. In team competition, Team Lapua/Brux/Borden won the F-Open Division, while Team McMillan finished first in F-TR Division. In the Sling Division, Team USA National Hayes topped the field. Congratulations to the winning teams.

View Complete SWN Match Results on McMillan Facebook Page »

Berger SW Nationals Ben Avery Wind

Berger SW Nationals

Wicked Winds on Saturday Challenged Competitors
Saturday’s weather was not kind to shooters. Along with cloudy skies came wind — lots of it. The wind was veering, and gusty — with significant changes in velocity. It was hard to predict the cycles — if they could be called that. Erratic was more like it. Many shots were out in the 7 and 8 rings. One champion-level shooter told us: “That was ugly — I got my clock cleaned”. Another shooter said “I ran out of paper to hold off”. At one point, Team Lapua/Brux/Borden (LBB) waited over 30 minutes to take a shot, hoping to get into a steady condition. The patience paid off. Team LBB shooter Jay Christopherson’s final shot (after the long wait) was a 10.

Berger SW Nationals Team Lapua Brux Borden

Above is a view from a spotting scope during the 1000-Yard Team Match on Saturday. During the course of the day, there were many 7s and 8s showing on the targets. One competitor said “the wind was so bad, I was holding off the frame”.

Berger SW Nationals Team Lapua Brux Borden

Team Lapua/Brux/Berger shot great in tough conditions on Saturday to win the F-Open Team competition. Second from left is Jay Chistopherson, AccurateShooter.com’s System Administrator. When he’s not shooting, Jay works hard to keep our Shooter’s Forum and content sites running smoothly.

The team announced: “Team Lapua-Brux-Borden pulled off a major win today at Berger SW Natinols. Conditions were very challenging but our wind coach was able to keep up with the conditions. Our rifles shot very flat which allowed us to rack up points and Xs. We have a great team and amazing sponsors: Lapua, Brux Barrels, Borden Actions, Cerus Rifleworks. Team members: Jay Christopherson, Eric Cortina, Steve Harp, Tod Hendricks, Pat Scully, and Bob Sebold. Notably, Bob Sebold also won the 2018 Berger SWN Individual F-Open title, making him a double champion.

Eliseo Tubegun with Nightforce Competition scope. These versatile rifle chassis systems are produced by Competition Machine in Cottonwood, Arizona.
2016 Berger Southwest Nationals Phoenix Arizona AZ

Berger SW Nationals Team Lapua Brux Borden
Photo by Sherri Jo Gallagher.

There couldn’t be a match without the dedication of the folks who work the pits. At the Berger SWN, competitors did pit duty, ferried by trailers, and there were also some volunteers.

Berger SW Nationals Team Lapua Brux Borden
Photo by Sherri Jo Gallagher.

They say behind every successful man is a good woman. Derek Rodgers, current F-TR World Champion, is no exception. His wife Hope Rodgers was on hand throughout the SWN to cheer on her husband.

Berger SW Nationals Team Lapua Brux Borden

For many sling shooters, the Berger SWN is the second most important event of the year, right after the NRA Championships, held at Camp Perry (OH) and (now) Camp Atterbury (IN). Check out those patches.

Berger SW Nationals Team Lapua Brux Borden

Industry Report — Berger, Lapua and Capstone Precision Group

Last year Berger Bullets was acquired by the Nammo Lapua Group. Berger Bullets, along with Lapua Products, SK Ammo, and Vihtavuori Powder, are now distributed in the USA by the Capstone Precision Group. Berger will continue to offer its full line of bullets, plus Berger-branded Ammunition (formerly ABM Ammo). Likewise Lapua will continue to offer its superb caftridge brass, plus Lapua’s full line of bullets and loaded Ammunition. In this video, Capstone’s Director Bill Gravatt explains how Capstone is working to expand the availability of Lapua and Berger products. In addition, Eric Stecker explains how Berger Bullets can increase production significantly, now that Berger is operating in the large Nammo/Lapua facility in Mesa, Arizona.

Today is the last day of the Berger Southwest Nationals. After the cancellation of Sunday’s 1000-yard matches due to high winds, this year’s 2018 SWN concluded with the Award Presentations. We watched as scores of medals — along with heaps of cash and Berger bullets — were handed out. AccurateShooter.com also awarded prestigious Corinthian awards to Nancy Tompkins (Sling) and Rick Jensen (F-Class).

Berger SW Nationals Team Lapua Brux Borden
Photo by Sherri Jo Gallagher.

Team McMillan was the top-performing F-TR squad at the Berger SW Nationals. The team includes many former members of the all-conquering Team Sinclair.

Berger SW Nationals Ben Avery Wind

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February 11th, 2018

Bullet RPM and Drag — How BC Changes with Bullet Spin Rates

Bryan Litz bullet rpm BC Drag ballistics coefficient twist rate

You may not realize it… but to get the optimum BC from your bullets (i.e. the lowest aerodynamic drag), you must spin the bullets fast enough. Bullet drag increases (as expressed by lower BC) if the bullet spins too slowly. Bryan Litz of Applied Ballistics explains how BC changes with twist rates…

More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.

Any test that’s designed to study BC effects has to be carefully controlled in the sense that the variables are isolated. To this end, barrels were ordered from a single barrel smith, chambered and headspaced to the same rifle, with the only difference being the twist rate of the barrels. In this test, 3 pairs of barrels were used. In .224 caliber, 1:9” and 1:7” twist. In .243 caliber it was 1:10” and 1:8”, and in .30 caliber it was 1:12” and 1:10”. Other than the twist rates, each pair of barrels was identical in length, contour, and had similar round counts. Here is a barrel rack at the Applied Ballistics Lab:

Applied Ballistics used multiple barrels to study how twist rate affects BC.

stability gyroscopic ballistics coefficient drag twist rate

“The Modern Advancements series is basically a journal of the ongoing R&D efforts of the Applied Ballistics Laboratory. The goal of the series is to share what we’re learning about ballistics so others can benefit.” –Bryan Litz

Barrel twist rate along with velocity, atmospherics, and bullet design all combine to result in a Gyroscopic Stability Factor (SG). It’s the SG that actually correlates to BC. The testing revealed that if you get SG above 1.5, the BC may improve slightly with faster twist (higher SG), but it’s very difficult to see. However, BC drops off very quickly for SGs below 1.5. This can be seen in the figure below from Modern Advancements in Long Range Shooting.

The chart shows that when the Gyroscopic Stability Factor (SG) is above 1.5, BC is mostly constant. But if SG falls below 1.5, BC drops off dramatically.
stability gyroscopic ballistics coefficient drag twist rate

Note that the BC drops by about 3% for every 0.1 that SG falls below 1.5. The data supports a correlation coefficient of 0.87 for this relationship. That means the 3% per 0.1 unit of SG is an accurate trend, but isn’t necessarily exact for every scenario.

It’s a common assumption that if a shooter is seeing great groups and round holes, that he’s seeing the full potential BC of the bullets. These tests did not support that assumption. It’s quite common to shoot very tight groups and have round bullet holes while your BC is compromised by as much as 10% or more. This is probably the most practical and important take-away from this test.

To calculate the SG of your bullets in your rifle, visit the Berger Bullets online stability calculator. This FREE calculator will show you the SG of your bullets, as well as indicate if your BC will be compromised (and by how much) if the SG is below 1.5. With the stated twist rate of your barrel, if your selected bullet shows an SG of 1.5 (or less), the calculator will suggest alternate bullets that will fully stabilize in your rifle. This valuable online resource is based directly on live fire testing. You can use the SG Calculator for free on the web — you don’t need to download software.

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