Actually its not a new chambering, its a re-introduction from back in the 60s I think. It has been mostly overshadowed by the 264 Win. Mag, and 7 MM Mag.
Obtained velocities are about 100 fps faster than a 24" .260 (about the same as a moderate velocity 6.5x284), but barrel wear is probably 30-40% faster than the .260 (although about 10% slower than the 6.5x284).
hmm.... ok well thats cool i was just looking at the remington catalog and it had an "*" beside it and one the bottom it said "new for 2004" so i was just wondering i have never heard of it before so i was just wondering i own two 7mm rem mags and i love them,maybe i'll own a new rem 700 in teh next few years in that chambering