I’m currently looking at getting a new rifle that will be used for an upcoming hunt as well as long range shooting. It’ll be in 300 Win Mag.....
What would a long-range rifle weigh anyway? I don't have one. If I were to guess, I'd imagine somewhere between 11 and 17 pounds or more. Even a hunting-weight rifle at 8 pounds with a 3 pound optic will be 11 pounds. If you hunt from a blind, maybe that's practical. I wouldn't want to hunt with anything that I'm not willing to spend an hour on the stair climber with.
What’s your definition of “long range” there are plenty of standard weight rifles that are capable accuracy wise of hitting the vitals of an animal out to 7 or 800 yards. And more than a few that are capable past 1000 yards. That’s with a high quality scope of standard weight.
It was the OP's definition that matters.
The outfits we are looking at for our Elk Hunt indicate no shots longer the 600 yards. I’m looking for a lightweight hunting rifle with good optics to bring with me. I’m thinking a Tikka T3X Lite or Lite RoughTech but fluted or not is a question I’m looking at now.
In your original post, you indicated the rifle would be used for an upcoming hunt
as well as long range shooting. 600 yards would meet anyone's definition of long-range hunting, but it would not meet most people's definition of long-range shooting. Even so, what most people consider "long range shooting" is better accomplished with a rifle and optic suited to it, and they are not the same as a rifle and optic suited to hunting.
Don't buy a hunting rifle or a long-range rifle based on advice from a gun shop or an internet forum without going and seeing what people who are doing what you want to do are actually using to do it. If you're using an outfitter or guide for the elk hunt, ask them what they recommend and what successful clients with a similar level of experience to yours are using. If you have a place to do long range shooting in Massachusetts, go there and see what people are using and then talk to them about what they would change, if anything, and why. Do you even have a range that goes past 300 yards? If so, are the people there shooting a benchrest style discipline like F-class, or Palma, or are they shooting Practical Precision steel?
Hunting can be accomplished a lot of ways. Elk hunting can be done with a SxS or a pack horse carrying the rifle most of the way. Then a long-action (300 WM), heavy-stocked rifle with a heavy barrel and optic with a giant objective and rock-solid erector could be quite practical. It can also be accomplished backpacking. In that case, the saying is, "ounces equal pounds, and pounds equal pain." Your success backpack hunting is more assured with an ultra-light, short-action (308-class) rifle with a lightweight optic (16 oz or less). For that weight, the erector is not as likely to track as well, and the objective is likely to be smaller. Compare the weights of a Swarovski Z5 (hunting scope) and a Nightforce ATACR (long range scope).
What experience do you have hunting deer? I've not had any myself, but I have helped others do it, as in being right at their side through the whole hunt. I've been with beginners to intermediate (5 years of hunting experience). Based on that experience with multiple hunters, I would strongly advise against taking a shot longer than 200 yards. For a hunter's first shot on big game, I would strongly encourage getting 150 yards or closer. If the shooter were particularly talented and had considerable skill in a discipline other than hunting, and they had hunted at least once before, 300 yards would be the most I would not oppose. I know life-long hunters with decades of experience hunting all over the west, three or four hunts per season in multiple states, who will be honest with me. They screw up 500-yard shots, and it ruins their season. For a beginner to attempt a 500-yard shot on an elk would be
idiotic. Besides, it's far less exciting when you can't get any closer than that. What is worth much more than making a 500-yard shot is actually
hunting to get closer. Even if I were to have a shot at 500 yards, but lose the opportunity while attempting to get closer, I would attempt to get closer dozens of times, even if it took several seasons, before I would rather take the 500-yard shot and take home what I would consider to be a concession prize.
Rather than thinking what rifle will allow me to make a 600-yard shot, I would think: what rifle will hinder me the least in my effort to close less than 200 yards.