Some magnums, like the 338 Win Mag don't lose that much with a shorter barrel.
With my 20 inch 338 it is ~25fps per inch for 24 inch barrel with 225 and 200 grain bullets. I found with heavier bullets (especially 275+) it could be super minimal ~12 FPS an inch. Usually using 4831
I might have a “ fast barrel”. With max loads my 275 Speer loads were ~50 FPS off the book velocity
I think 338 works as a “ guide gun” chambering because it fits in a standard actions, can be built into a light gun because of this, shoots heavier than average bullets , can be easily handled in a light gun, is relatively inexpensive components wise and follows the general trajectory of “standard rounds” for follow up at closer distances
I will never, for the life of me understand why 225 bullets are popular as a “do all” load in a chambering with such a diversity of bullet weights, but you could certainly happily hunt deer, moose and probably whatever else with that weight
You could do a lot worse than a 7-8lb scoped 338 with a 20 inch barrel as a do it all Canada gun, but if most of “ all” is going to be white tailed deer I don’t think it would be my first choice (signed someone who moved from Northern BC to Saskatchewan).
Still something appealing about a short barreled, lightweight(ish) 338 wm. Sights, synthetic stock and stainless steel optional.