What caliber for F class 600 & 1000 yards

[JASmith]

you'd be surprised because other cartridges like the 6.5x47 will turn in the same numbers as a hot 260rem even with it's smaller case capacity. Sometimes you just get a fast barrel.
Yea verily! It is nice to have a rifle that shoots flatter and bucks wind better than your friend's rifle.

BUT, one needs to be particularly vigilant when he has a 'fast' barrel. "Fast" does not necessarily (should we say rarely?) mean efficient, so the price normally paid for a 'fast' barrel is higher pressures to produce that higher velocity.

The.243 and Dasher are already running at pressures that are rather close to the limit for brass, so margins are smaller. Those smaller margins mean that it is easy to go too high.

So, closely checking one's brass is doubly important when the barrel seems fast.

[Alleycat72]

My daughter's 6mm brx is running 3050 with 105 hybrids, but she has a 30" barrel.

[PAPERKILLER]

Thanks for all your replies guys. I am still trying to weigh, out the plus and minus of each. The regular 6 BR sounds pretty good, very efficient and long barrel life. I really don't want to turn necks if I don't have to. Would probably look for a barrel with a .272 neck throated for 105-115 bullets. Should still be able to get 2850-2900 fps in a 28" barrel. The Dasher intrigues me though. But it sounds like a lot of work for 150-200 fps. I have heard the rumors of Dasher brass being made. That would sure be sweet. The 6.5 x 47 sounds good too. Lapua brass with a small primer would certainly hold up better in near max loads. I would probably try to find a load with 120 to 130 pills as they seem to get near that magic 3000 fps that would keep me under the 25 moa to 1000 mark. Anyway, I'll keep playing with the ballistics calculator and see if I can figure out my next barrel/build. Please keep the input coming. I can use all the help I can get.....Rocknut

[JASmith]

Those are all excellent choices.

An alternative might be the 6mm XC with a case capacity of 50gr H2O. Nominal velocities seem to be close to what you are looking for, especially if you are OK with a 28 - 30 inch barrel. Norma makes brass for it although Midway currently (9-18-14) indicates "out of stock - no back order" along with a huge number of other fine cartridges.

[normmatzen]

I shoot a 6BRX and a straight 284 WIN. Both do good at 600 and 1000 but the 6BRX seems the best of the two. 3000 fps is a great equalizer! And it still gets good barrel life. The 284 is also much more expensive to shoot.
My friend in Australia is gathering parts for a 6.5X55 for his F Open. This cartridge is not well known or used much in the USA, but is in Europe and Australia. Off the shelf cases are available from 2 or 3 European makers and the Swedes used this cartridge for many years and it is nearly unbeatable for accuracy. It uses much less powder than a 6.5-284 and is a bit easier on barrels.

I think if I did it over, I would have built a 6.5X55 or another 6BRX. Probably another 6BRX. Why the 6BRX instead of a 6 Dasher? They are so close one should consider them identical. But the 6BRX is easier to gear up for and fire form. Either way, the 6 Dasher or 6BRX will prove to be economical, easy to tune loads and fun to shoot.

[normmatzen]

It turns out the 6BRX and the 6 Dasher are very close in all aspects. one that is different tho is that the neck angle of the 6BRX is the same ass the 6BR. That means it is the easiest to fire form and tool up for. I went that route a couple years ago and bought 200 Lapua 6BR cases. I loaded them with some good 105-108gn target bullets so the bullets were into the lands 0.030 or so, 30gn of Varget and you are good to go. If you want, you can actually shoot in matches with the fire forming! Accuracy is great and nothing could be easier.
The nice thing about the 6BRX is the ballistics are virtually the same as the Dasher and the barrel life is way up there and velocity is typically 3000 or 3010 for good ballistics. I also have a 284 WIN F class gun and the 6BRX out-shoots it!