That's gonna be a heeeavy and long gun. If you really feel that you need the range of a magnum, I would consider a 300 Win Short Mag in a short action with a 20" barrel. Huge weight and length savings with almost the same ballistics.
I also have strong feelings about chassis that have me touching exposed aluminum or that have a lot of snag points.
If we kinda flow chart this out:
- If it's deer/black bear/antelope or similar or smaller, a magnum is overkill. Most shots are taken within 200yds, very few present past the 500yds that a .308 is capable of.
- If it's Elk, and you're in very open country like E. Oregon or some places in Idaho or Montana, etc., can present, then a magnum can make sense.
- If it's Elk season, the weather probably sucks and I wouldn't want to touch anything aluminum
I switched back to a 6.5 creedmoor for long range shots using 142gr Accubond Long Range cartridges and a lightweight .308 AR for anything else after running the numbers. 700-800yds is the absolute max range I'd take a shot on an animal because that is cross-canyon distance where you're really messing with different with layers and a 1+second flighttime. If I shoot an Elk at 650 with an ABLR I'd be happy. If I shoot a blacktail at 50yds with the same round I'd be happy, but if I took that shot with a magnum it'd destroy a lot of meat.
If you want the magnum though, I'd shorten the gun up with a short action magnum cartridge and shorter barrel in the 20'ish range. I'd also consider how much you're walking with it. Last season I did 13 miles on the last day. My gun with a can was 9 pounds and that didn't bother me, and I wouldn't want to go more.
That scope is also a bit heavy and has a reticle that's hard to pick up outside of ideal situations or at close ranges. Great scope, but I don't think it's a good option for hunting.