RE: remington 770
The 770 is an update to the 710. I was able to handle a 770 at the Bass Pro Outdoor World in Nashville last month. Since I have a 710, I wondered what might be different. Mechanically, the biggest benefit is that the bolt operates more smoothly. The Remington web site mentions an updated magazine release also.
Other than that, the black stock instead of a gray one is the biggest cosmetic difference. Until the last couple of years of production, I believe the 710 had a nylon/plastic insert (mine does) in the receiver instead of being made from all steel. Some folks didn't fancy that idea much, but probably the same types who - I'm sure - thought the end of the world was coming with the advent of synthetic stocks.
If you're like me and don't get the chance to big game hunt but for maybe a dozen days each year, I'm sure it will suit your needs just fine.