Gent's I don't have a Chapaius or 9,3x74R, but I do own a Merkel 375H&H 140-2 Safari. The gun is nearly perfect. It was less than $8000 new, the fit and finish is flawless, has an unconditional 5 year warrenty, and shoots like a house of fire. I recently competed in the Big Game Club Match at Lodi and walk away with 3 trophys. I won the nitro 1 class, pulled a second in charging animal and snap (8 shots in 35 sec.) competing against bolt guns with scopes! And I did not do that sissy one barrel shooting. I shoot both barrels.
Now, what about the 375 H&H? It packs more punch than the 9,3 when you need it, but can be loaded way down, as I do with my 235 grain soft points. My one/two shots are lightning fast. Finally, it only cost me $0.75 per shot.