I reckon there's good reason that the little round looks like a miniture Whelen, the 222 Remington is a scaled down version of the 30/06 that Mike Walker of Remington design dept. came up with. Kimber came out with the .257 Kimber, offered briefly in the Kimber of Oregon models back around the 70's somewhere. The idea,based on a 222 Remington Magnum cartridge case necked up to 257 and blown out a bit like an Ackley improved didn't catch on. As I recall it could launch a 100 grain bullet at 2700fps (based on a foggy memory). The CZ 527 mini Mauser ought to be an ideal available rifle to cobble up into a similar rig these days. The 6.5 Grendel cartridge fits the little CZ 527 perfectly, and offers 308 punch at long range,with a flatter trajectory. Yet it is a very usable varmit round with lighter bullet weights. The Grendel, by the way, whips the Remington 6.8 in every catagory. Brockman's gunsmith specializes in rebarreling the little CZ rifles to the Grendel round, which was designed as the maximun power cartridge that would fit the AR rifle platform, in a bolt gun it is better yet since working pressure can safely be elevated into the 50-55,000 psi range.
I still have the original Wooters/Guns & Ammo article around here someplace on the Copperhead. It took us 15 or maybe 20 years from that article but Dad and I finally built one, biggest change being we put ours on a sporter stock instead of the mannlicher. Not sure much of anything but 75gr HP, either Hornady or Sierra, has ever been through the barrel but woe be to any varmint inside 200 yards. Mine carries a Leupold 2.5-8.
Comment above about it being a neat looking little round is dead on. Always reminded me of a miniature "Whelen". Sort of hits like one too.
