Lengthy discussion here. IMO, the comparison is 'apples and oranges'.
The .375 H&H is a MEDIUM BORE cartridge that is broadly applicable and can handle buff in a pinch f backed by a appropriately armed PH. The 375 can be used at distances up to 250 or, perhaps, 300 yards, so it is a 'heavy PG rfile' that can easily handle cats and stretch to buffalo as well.
The 404 Jeffery is an over 40 caliber (large bore) cartridge designed for dangerous game shooting. It can be applied to PG, but NOT at the ranges that the 375 H&H excels at. I know... I used my 404 to shoot a bull eland at a bit over 200 yards and it did the job, but I felt that this was a stretch. The 375 would have been much better for that shot.
I own both a 404J and a 375 H&H and appreciate both, but they are not truly interchangeable, IMO.
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