For a couple years now I have been a remington guy for my hunting rifles. Currently I'm shooting a Remington 700 SPS 7mm Rem Magnum, shooting Hornady 139gr BTSP InterLock being pushed by 67.5 grains of powder. I'm good shooting right now up to 400 yards, and going to keep working on perfecting those shots 0-400 with that rifle. I'm looking at buying a rifle to shoot a little bit further with, up to probably 700 yards or so. Right now the Sendero is my choice of guns, I just don't know which caliber would be best. I'm hunting whitetail currently, but want to take antelope, elk, mule deer and hopefully moose and bighorn at some point in my life. I'm looking at the 300 RUM and the 7mm RUM and wanting to know the differences, pros and cons, and suggestions on which performs better for hunting situations like I've described. I'm new to the forums, just joined and figured this is my best resource for information on the two. Thanks.