A Remington 700 .30-06 has been my favorite rifle for 20 years now. I bought it in Alaska when I was stationed up there and used for black bear and caribou. Down here it has taken lots and lots of deer white tail and mulies both. It has been used in blizzards up in Montana, deep cold in North Dakota and of course in Colorado. It has a Leupold VXII 3x9 on it and I almost always use a handload of 4350 and a Hornady BTSP 150, 165 or as in Alaska I used a 190 grain bullet.
But for the last two years I've used a CZ 550 6.5x55 Swede and I harvested two very nice mulie bucks with it. Both didn't go more than 20 yards. It also wears a Leupold and I use handloads of 4350 and a 140 SP Hornady bullet.