RE: 8mm rem mag.
Mnhunter is right: The 8mm Rem Mag is, quite simply, a monumental cartridge. It can zip 220gr super-premium bullets out of the muzzle easily at 3000+ fps, and that makes it suited for just about any game on Earth.
It really is way too much for deer, but a lot of people like the .300 RUM for that purpose, so if that's your cup of tea, go for it.
There is now a very good selection of 8mm bullets out there, so a handloader could make a terrific large-game/African rifle based on this cartridge.
It is a shame Remington introduced this number in such a huge case, with all the associated recoil and muzzle blast. It seems to have doomed all 8mm rounds, previous and future, and the .323-cal bullet in different size cases is really a very versatile size. The 8mm-06, 8mm/.308 and wildcat 8mm's based on the short mag cases would make a whole lot of sense to the one-gun North American hunter.
Good Dogwork and Good Hunting