I doubt any are. Why would anybody chamber a rifle in 6mm Rem? It's virtually identical to the more common .243. Having owned both, as any good 788 collector will, I can say that neither holds anything above the other in performance. The .243 is nice because I can use readily available .308 to make the cases... and do. I don't use 6mm in general because it's sandwiched between .22-250 and 308. I don't see a need here, especially with the volume of calibers wedged in there such as the 220 Swift, .243, 6mm remington, 257 roberts, 260 Remington, 6.5 sweede, 7mm-08, 7x57 Mauser, etc. All good calibers and I own a few. When I go to the field, I don't need an inbetween caliber.
[This message has been edited by badgerarms (edited July 16, 2000).]