This story was first published a few years ago. It’s still an interesting topic for benchrest shooters. The 30 BR (a 6mmBR necked to.30 caliber), currently dominates the benchrest-for score game. A 30 BR Improved has some advantages, especially when the winds are tricky or strong. Al Nyhus explains the 30 BRX wildcat in this article. Al claims that he can get 150-200 FPS more running Hodgdon H4198 than the traditional 30 BR. This can mean less wind drift. You can also pursue a faster speed node which can improve accuracy with some barrels. Forum member Al Nyhus has competed in VFS matches with the 30 BR cartridge. Al has been working to improve the 30 BR cartridge, which delivers more velocity. Al’s 30 BRX cartridge was inspired by the 6mm BRX, which is popular in 600-yard benchrest competition and across-the-course competition. The 6mm BRX cartridge has the same sidewall profile as the 6mmBR case and the same shoulder angle. The 30 BRX retains its 30? shoulder used on the popular 30-BR cartridge. Al reports: “Thought that you might like to know what I’ll use in my VFS gun this year. It’s a true BRX 30 — a 30 BRX with the shoulder moved forward 0.100. With the standard BR shoulder angle. Stan Ware from SGR Custom Rifles made one last season for Steve Grosvenor. I was very impressed with the gun’s performance. The 30 BR barrel of my VFS gun had to be replaced, so the new 30 BRX was chosen. 30 BRX Delivers 150 to 200 FPS More Velocity Than 30 BR
Al claims that his 30 BRX provides a solid 150-200 fps speed increase over the 30 BR at its top. However, it requires only 2.5-3.0 grains of HodgdonH4198 to do this. The average 30 BR case holds 40.8 grains of water while the 30 BRX has 42.3 grains. This is roughly 4% more. The 30 BRX provides a 7% increase of velocity and a mere 4% increase of H20 capacity. This is a pretty impressive efficiency. [Editor’s note: Assuming that 34 grains of H4198 are a typical match load for 30 BR match loads, Al’s 2.5-3.0 grain increase for the 30 BRX is approximately 7.5-8.5% in actual powder burn. This explains the higher velocity. Nyhus decided to test an “improved 30 BR”? Al explains that the 30 BRX was designed to operate at a higher velocity than the standard 30 BR, but retain the easy-tuning characteristics and ease of use of the 30 BR. We wanted to use the same powders as the 30 BR, and maintain the same operating pressures. The increased velocity makes the 30BRX more difficult to shoot. Al doesn’t think so. “In a 13.5-lb HV Gun, the 30 BRX Case is a pleasure shooting with just a flea bit of recoil.” The 30 BRX will be popular in Score Competition.
The 30 BR is an extremely accurate cartridge that dominates Benchrest for Score competition. The 30 BRX will make the standard 30 BR obsolete. Nyhus doesn’t believe so. Al believes that the 30 BRX gives a small, but important advantage in certain situations. “On any given day it’s the shooter who hits the flags best, makes the fewest mistakes, and ends up on the top. If you press the trigger wrongly, no amount of velocity can save you. Missing an angle change or switch at 200 yards can result in 3/4. The bullet displacement on the target cannot be compensated with 200 fps. This is the hard truth of benchrest shooting. Randy Robinett said that BRX can be enough to make a close-but not-cigar 10 at 200 yards into a ‘X’. Or turn a just-over-the-line 9 into a beggar 10.” A score match is fiercely competitive and an extra 10 or more X could make all the difference between a podium finisher and an also-ran.
