If you don’t like the recoil of it, I’d either load some easier shooting stuff or maybe something like a 9.3x62 would be a better fit. Adding that much weight to but or about any rifle sounds like a horrible idea for balance as Don mentioned.
As for adding weight and effecting balance, I once added some weight to the butt of a Savage heavy barrel 22lr to see how it would react to bench shooting. Even at that it didn't feel right, butt heavy as suspected. For hunting rifle, I wouldn't recommend it.