Hello all, I am getting ready to build a new varmint rig, and I am trying to figure out what cartridge to use. I will be shooting small varmints like Pdogs and Squrriels. I want the rifle to be able to be deadly accurate out to 600 yards. It will be a high volume shooting rifle, so I want a cartridge that will give me excellent barrel life. I have been told, by many, to go with a no-turn neck 6BR with a 1-8 twist barrel. I was thinking about going with a regular .223 with a 1-7.5 twist barrel to shoot the heavier 55 to 80grn .22 cal bullets. From what I have read, the 6BR sure sounds like it's the perfect varmint cartridge. I would like to hear what you guys think. Also, the majority of my varmint hunting will be done from 400yards to 600 yards, so I am diffenently going to go with a fast twist barrel. Any help would be great, thanks.