May 6th, 2009

Amos Sets 600-Yard Record with 'Universal' Benchrest Rifle

Roger Amos (aka Expiper) is a long-time friend of this website and member of our Shooters’ Forum. We were pleased to see that, while competing at the NBRSA 600-yard Nationals, Roger set a new NBRSA Light Gun 3-target score record of 145-4X. Roger set the record with his 13.4-lb Panda-actioned, 8-twist 6BR, the same gun he shoots in 100/200 yard benchrest matches. Roger has demonstrated that a single gun can be competitive at multiple distances. This concept of a “universal benchrest rifle” is something we’ve advocated for quite some time, as we would like to see more 600-yard shooters compete at 100/200 and vice-versa. Also, with the tough economic times, it makes good sense to have one rifle that can do double-duty. Roger explains that his record-setting rifle “is typical of what I [now shoot] because of the high cost of building a target gun that is only legal/shootable at one distance or discipline. I am disabled and can’t carry a heavy gun because of my back. Out of necessity came up with this ‘universal rifle’ solution.”

Amos Universal BR rifle

Roger’s record-setting 6BR features a 28.5″ Krieger barrel (UHV profile), with a .237″ bore, .271″ no-turn neck, and .040″ freebore. That freebore length is much shorter than on most 600-yard guns, which typically have .090″-.120″ freebore. With an .040″ freebore, Roger can shoot both the 100+ grain bullets as well as the 62-68 grainers. At 600 yards, Roger runs Berger 105gr VLDs, .015″ into the lands, pushed by Reloder 15 and Fed 205M primers.

Amos Universal BR rifle

Fast-Twist Barrels at Short Ranges
Roger tells us that: “I have been shooting 8-twist barrels for several years now at 100-200-300 and they will shoot just as well as a traditional 14-twist (point blank) barrel … IF you use GOOD bullets. I have found that Barts and Fowler 62-68s will stand the extreme rotation associated with 3600+ fps and 1:8″ twist. Some bullets can’t take it. You just gotta try whatever you have and see for yourself. I have found the most accuracy at 100-200 with the 66-80 grain Fowler bullets or the 80gr Bergers. At 300 yards the 80gr Berger or 90gr Berger BT are excellent! At 600-1000 yards, the Berger 95gr VLDs can outperform the 105s because of their extra speed (although the 95s have a lower BC, their greater velocity can offset the BC advantage of the heavier bullet.)

Most of my stocks are around 22 ounces and give a finished weight of approximately 12 pounds. My Kelbly Klub stock on this gun is 48 ounces, for an all-up weight of 13.4 pounds. To help with balance, this particular stock has extra matrix in the fiber and is heavier than normal for point-blank guns. This gun can make weight as a Heavy Varmint but not as a Sporter — even if I used a 5-lb barrel.”

Pre-loading vs. Loading at the Match
Roger often loads at the range, but this wasn’t feasible at the NBRSA 600-yard Nationals. Roger explains: “When shooting ‘point blank’ (100/200) events, I usually load at the match like the majority of shooters. However this 600-yard event in Sacramento required airplane travel. These days, when flying, you are very limited as to cargo weight. Also you can NOT carry gun powder or primers. In your checked luggage, you are limited to 5 kilos (11 lbs.) of LOADED ammo and two long guns (or 5 pistols). Accordingly, I couldn’t take my dies/press/etc. with me, so I preloaded for the 600-yard Nationals.”

Permalink Competition, Gunsmithing 4 Comments »
May 6th, 2009

Berger Introduces 6.5mm and 6mm 100-grain Bullets

You may have heard rumors about a new 100gr projectile from Berger Bullets. Eric Stecker, Berger’s Master Bulletsmith, confirmed that there will be not one but TWO new 100gr match bullets coming soon from Berger, one in 6mm and one in 6.5mm. These are both boat-tail designs using J4 jackets. Eric explains: “Both these bullets are based on Berger’s proven designs, with standard length ogives and 9° boat-tails. Nothing radical. They are built in response to shooters’ requests to expand our bullet line-up to include new weight options in 6mm and 6.5mm.”

Berger Bullets

New 100gr 6.5mm Bullet for High Power
Berger’s new 6.5mm 100gr BT Target projectile provides a low-recoil, lighter-weight option for target rifle shooters using the 6.5×47 Lapua, 6.5 Creedmoor, 260 Rem, and 6.5-284 cartridges. The new 6.5mm 100-grainer was created in response to requests from High Power and Across-the-Course shooters for a lighter-recoiling, accurate boat-tail bullet for “short line” work. We predict this bullet may also work well for varmint and small-game hunters. This bullet features a short boat-tail and a “mildly secant” design which should work well either seated into the lands or jumped away from the lands. Bryan Litz says: “it’s definitely not a VLD, but it has a different ogive curve than a typical tangent-ogive bullet.” The shorter length of the 100gr bullet, compared to 140gr-class 6.5mm bullets, should also allow tactical shooters to easily load their ammo to mag length. The calculated BC of the new bullet is 0.370, significantly higher than flat-based 100gr 6.5mm bullets from other manufacturers. A minimum twist rate of 1:10” is recommended for Berger’s hew 6.5mm 100gr Target Bullet.

Berger Bullets

New 100gr 6mm Match Bullet — More Velocity Than 105/108
Long-range benchresters have had great success with the Berger 108gr match bullet, introduced in 2007. Given the popularity of its tangent-ogive 108, Berger has been developing a shorter, lighter version, which can shoot faster than the 108 in small cartridges such as the 6mmBR, 6mmAR (6-6.5 Grendel), and 6 PPC. The new 6mm 100-grainer will be very similar to the 108. The 100 has the same ogive curve and boat-tail as the 108 but has a shorter OAL and shorter bearing surface (0.368″ vs. 0.409″). A minimum twist rate of 1:8” is recommended for the new 100 — same as for the 108. In a 6BR rifle, the 100-grainer’s reduced bearing surface, combined with reduced mass, should enable Berger’s new 100gr 6mm bullet to fly 50-70 fps faster than the 108 (with charges of equal pressure).

Berger Bullets

However, there is a trade-off. Being shorter and lighter, the 100-grainer has a lower BC compared to its 108gr big brother. While the Berger 108 has a 0.511 BC, the calculated BC for the 100-grainer is 0.475. That BC difference will show up at long range, but the extra speed of the lighter bullet may enable it to reach a higher, optimal “velocity node” which may deliver superior accuracy in some rifles. We will be testing the new 100-grainer soon. In a 6BR that might max out at 2850 fps with the 108s, we predict the 100gr Berger should run close to 2900 fps. In a 6BR that delivers 2900 fps currently with the 108s, you may see 2950 fps (or more) with the new Berger 100s. The 2900-2950 fps speed range is a well-known “accuracy node” for both 6mm and 6.5mm bullets.

Permalink Bullets, Brass, Ammo, New Product No Comments »