A 3-18 is ALOT of scope for a 375. I've hunted with different 375s since 87 . Highest power I've ever had on any of them was a 2-7 . I also do the bolt out bore sight method. The 3 classic bullet weight/velocity , factory ammo loads were designed to do just what Greyfox described. 300 gr softs and solids @ 2530 ish fps = dead on @ 100 270 gr softs @ around 2700 fps = dead on @ 200 And 235 gr softs @ 2800 + fairly close to being zeroed @ 300. Ttbomk the 375 H+H Belted Magnum was the world's first all around rifle. Designed for 3 different bullet weights and velocities to be used on different animals. And ranges to target. But with only 1 zero of the sight. ALOT of the impetus for that was for its brother cartridge, the 375 H+H Flanged Magnum . for use in double rifles and single shots. It has a lower velocity for each bullet weight and shorter zero distances respectively. But still followed the same 1 sighting zero principle. Most people that use the 375 shoot the 300 gr and 270 gr bullets. I mostly use the 270 gr as I only hunt Alaska with it. The 375 isn't a ( stopper) cartridge per se . But, it has very manageable recoil and is really an easy cartridge to master if your rifle fits reasonably well. And it does hit hard . With a good shoulder shot , it generally knocks a brown bear down, and keeps it down long enough to put another bullet in the bear.