I could be way off base here, but from my experience shooting a lot of big 338's shooting 300 OTM bergers at 2960-3000FPS in lighter hunting configurations (9-11 pounds scoped and loaded) and have shot a lot of animals past 700 yards with them.. obviously not super long range but pretty far still..
I see a lot of attention is put on light weight parts excellent small light glass etc.. but I feel the most important part that a lot of builders and guys forget is the stock and how its designed too use for these uber magnums .. I've shot them all from an original styled KS sporter kevlar stock too a manners PRS2 style and everything in between..
Three of the absolute best for recoil management for larger recoiling rifles and still keep weight down in my opinion are the LPR nimrod, eh1 and MCM A3, all of the attributes of these stocks lend themselves too absolute best control of a heavier recoiling rifle and ability too spot hits at distance, of course all are teamed with either a terminator or the bad *** SRS Ti pro brakes.
The biggest factors for me from actually shooting these larger cartridges in light hunting rifles (and I shoot them a lot) consist of four things
1. straight comb with higher comb height = less face floating gets you a more consistent ,solid cheek weld without added weight of adjustable cheek piece or stock pack.
2. wider flat bottom with tapered sides and shallow degree of angle toe too grip.. =equals straight tracking directly into the shooter
3. little longer fore end so the distance from fore end bipod attachment too rear support contact are spread apart more equaling into a broader stance so too speak .. the closer you get the bipod too the rear support the more finicky these rifles become and you get a lot more muzzle rise!!
4. vertical comfortable grip that's slightly bigger with a palm swell which lends its self well too teach the shooter dont wring its neck let the gun recoil straight.
Just my two cents on my favorite rifles too have and when considering a lightweight 338 smasher that's where I always start!