Of the 3 rifles you are looking at I would pick the Savage first. If it is a newer model from Savage it will have the accu trigger. Even if it is the older model I think I would still get the Savage.
The 710 is not a bad rifle and several people I know have them and have gotten good use of them. One indiviual was able to get about a 1 1/2 inch group with his 710 in 30-06. I know no one with the Mossberg and while it is not a bad rifle. I don't have any personal experience with one or know anyone with one that has given me a result good or bad. So remember opions are like a particular body part! Everyone has one some people are one!
Which ever one you get go practice and have fun!