T2001,
If your going to be shooting the larger 6mm bullets, I strongly recommend the 243 AI, you will love it. Also, the Lapua 243 Brass is excellent!!!
If your going to use it for long range varminting, I would strongly recommend the 87grn V-Max with a .400 BC or the 105grn A-Max with a .500 BC. The other bullets will work, however, they do not kill the varmints as well as the 87grn V-Max or the 105grn A-Max.
If your going to shoot competitions with the rifle, I would highly recommend using the 105grn Lapua Scenar.
If you go with the 243 AI, you should get the following velocities with a 28" barrel;
1. 87grn V-Max around 3500fps
2. 105grn A-Max-you could push it faster, however, it will blow up once it goes over 3200fps. So watch your speed with this bullet.
3. 105grn Lapua Scenar, 105grn Berger, or 107grn Mk can be pushed around 3300fps.
One of my varmint hunting buddies uses a 243 AI for his varminting out to 1000 yards. His two favorite varmint bullets are the 87grn V-Max and the 105grn A-Max. He uses he 87grn V-Max for shots ranging from 100 yards out to 800 yards. When he shoots past 800 yards, he uses the 105grn A-Max.
He has made many kills, with the 87grn V-Max, at 1000 yards, so it can be used at that range too. For pure red mist, he recommends the 87grn V-Max. He also recommends H4350 and federal primers with the 87grn V-max and Reloader 25 or Retumbo for the 105grn bullets.
I don't know too much about the 6x47. I have heard that it is performing well. However, it will NOT give you the velocity performance that the 243 AI offers.
I have used and seen the 243 AI in action, once again I highly recommend this cartridge.
The 6BR is a excellent excellent catridge. However, if your wanting more velocity with the larger bullets, the 6BR will not give you the velocity performance of the 243 AI or 6x47. If you only shoot the lighter varmnt bullets, 55grn to 70grn, the 6BR would be the best choice. The 6BR with a 28" barrel will push a 70grn bullet at 3550fps. It shoots the 105grn bullets at 3000fps.
The 6x284 was mentioned above. It will shoot the barrels out quicker than the 6x47 or 243 AI. However, if you want a 6mm for pure speed and accuracy combined, the 6x284 will out perform all of the 6mm cartridges. It will shoot a 87grn V-Max out of a 28" barrel at around 3700fps and can also push the 105grn bullets at 3500fps.
If this rifle is going to be a low volume varmint rifle and you have other rifles you will use during your varmint hunts, I would strongly recommend the 6x284. The 6x284 is absolutely devastating on varmints. On our last varmint trip, one of the guys had a 6x284. It was awesome when he hit varmints with this thing. He was using the 70grn Nosler Ballistic Tip and pushing it out of his 30", 1-12 twist barrel at 4100fps. It was deadly accurate out to 700 yards. When this guy hit a squirrel, it blew them into tiny parts and the red mist was super cool!
Anyhow, good luck with your choice. If your dead set on the two cartridges, 243 AI and 6x47, I would strongly urge you to seriously consider the 243AI. You will love it!!!
P44
