Ladies and Gentlemen, lets get into the most popular 6mm cartridges in long range shooting. I’m going to start this by saying that there are numerous other ”wildcat” cartridges that sling 6mm projectiles, so if I left yours out and you feel it deserves an honorable mention, feel free to let me know and we can revisit it at a later time. FROM LEFT TO RIGHT IN THE ABOVE PICTURE (.243 WINCHESTER, 6MM CREEDMOOR, 6X47 LAPUA, 6 GT, 6BRX, 6 DASHER, 6 BRA, 6 BR NORMA.)
6BRX and 6 DASHER. Both these cartridges started as 6 BR NORMA cases and have been fireformed into their current and final form. Both of these cartridges hold roughly 3 grains more powder vs. a standard 6 BR NORMA. Thus yield much higher velocities over the 6BR. The two side by side look very similar because their basic case length. They have two different shoulder angles. Main reason for someone to run these is pursuit of higher velocities. Second, potentially better feeding in a magazine (This topic is widely debated. We cover this in the post about the “Bighorn Origin action.” We explain how the modern BR magazine can feed all the BR cartridges with zero malfunctions. The fireforming process can be a labor intensive one wasting powder, bullets and primers. You also have the option of hydro forming brass. The final product is a BR class cartridge with all the accuracy and barrel life advantages, and also opening a whole new weight class of bullet options for the hand-loader such as the family favorite, Berger 109gr Hybrids, and the Berger 115gr VLD Target. We have found that the Krieger 7-twist barrels perform amazing with these two and can help you yield 2900 FPS velocity with ease. We prefer the 6BRX for the fact that the shoulder angle is less aggressive over the Dasher and feed amazing. The 6 Dasher has a few pros that we have debated over such as the option now for factory brass from companies such as Alpha Munitions and Peterson. With that being said, we still stand with Lapua brass and until we do a full workup on the fireformed brass vs. the factory options, were going to render that argument an irrelevant one until further notice. Both these cartridges have a reputation for being surgically accurate and both would be our top choices for competitive shooters who dedicated shoot handloads.
The picture above you can see the slight witness mark on the BRX case (LEFT) where the case’s factory shoulder 30* used to be before the fireforming process. The shoulder is blown out .100 and allows for roughly 3 grains more powder. The 6 Dasher (right) has a 40* (Ackley) shoulder and holds roughly the same 3 grains more powder over the parent cartridge the 6BR NORMA. 6 BRX can use standard 6 BR Norma dies so switching over is relatively inexpensive and a major selling point for me.
These two cartridges are the 6BRA (left) and the 6BR NORMA (right). The BRA boasts a 40* (Ackley) shoulder over the standard BR. This allows a steeper flow into the neck of the brass for the powder and thermal event over the BR. This design is supposed to increase throat life on barrels and the brass once fireformed to Ackley holds a kiss more powder allowing you to reach speeds closer to a Dasher. With that being said, were seeing 2850FPS with 26” barrels and standard BR cases with H4350 powder and Berger 109s. The BRA is the easiest of the fireformed wildcats and is one of the allures to switching to it. Both have amazing barrel life. The previous 6BR barrel we tested lasted well north of 5000 rounds under 1/2 MOA before we pulled the barrel. We recommend the 6BR over the BRA merely because the performance gain of a few feet per second is out-weighed by the feeding issues associated with Ackley shoulder brass.
The picture above is the 6-Creedmoor (left) and the 6 GT (right). The 6 creed is a factory Hornady Ammunition option for people who do not reload. This our recommendation for all new shooters because the ammo options. It has the speed advantage over the 6.5 with also the very low recoil. 6 Creedmoor can push 108GR ELD north of 3000FPS with factory ammo and with Lapua small primer brass and handloads, break the speed rules for PRS. The downside is the associated barrel wear. We have seen really awesome accuracy with 6 Creed and have nothing left to be desired on that topic. Measured against a new cartridge 6GT, it does have factory ammo (although limited) and was designed by GA PRECISION to mimic the BR class cases. All without the associated feeding issues and was designed to run Varget class powders. Between the two, 6 creed, NO CONTEST. One final note, the last 6 creed barrel We ran hit 1800 rounds and still shot 1/4 MOA. Don’t believe everything you hear about 6 Creed barrels dying in 1000 rounds.
These are the “BIG 6’S.” From left to right, 6 CREED, 6X47, 6 GT. 6X47 is our favorite for handloads of the 3 above. We have seen speeds well north of 3100FPS with 6X47 and the brass life is great. Side by side against the 6 Creed, the 6X47 can run the exact same race but is a more accurate cartridge. The 6X47 parent case is the 6.5×47 Lapua. There are no factory options for 6X47. CROWNRIDGEBARRELWORKS.COM
Above you can see what a BR can do with a dialed in recipe for handloads at 100YDS. “PROOF IS ON THE PAPER.” The accuracy of the BR’s is unmatchable. For hand-loaders, it does not get any easier than this. We routinely make jokes that all you have to do is throw powder in a BR case and stuff a bullet in it, the thing will shoot tiny holes.
Above are 5 round groups with high mirage. BR class cartridges still perform well, even on a bad day.
6BRX and 6 dasher will both shoot “bug-hole” groups with very little load development. All these shot groups are performed with bipod and rear bag. Why Standard Deviation (SD) matters and how to lower those numbers!
All in all, this is a heavily debated topic. Let me start by saying, “form your own opinions!” and no matter what you choose, they’re all performers. With that out the way, LETS RANK THESE!
  1. 6BRX (Feeds the best, highest accuracy category, best speeds, idiot proof for reloading, has to be fireformed)

2. 6DASHER (Close second to BRX, highest accuracy category, nearly identical to BRX, has to be fireformed, most popular in PRS amongst pros)

3. 6CREEDMOOR (Best factory cartridge for PRS, super easy to handload, availability of brass is a plus, shorter barrel life)

4. 6BR NORMA (Highest barrel life, highest accuracy category, idiot proof for reloading, slowest velocities)

5 6X47 LAPUA (Insane speeds, only has reloading as option, mild finicky reloading)

6. 6BRA (highest accuracy category, easiest to fireform, not as easy to find accuracy nodes reloading but still easy)

7. 6GT (redundancy in design with BR MAGS available now, outperformed by 6 CREED and 6X47)

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