I suggest that you slug your bore before spending anything on special ammo. I've slugged a number of early 1888s and 1908 Mannlicher-Schoenauers and found their grooves to run around 0.327"-0.328" and in every case that I've tried, the 0.323" jacketed bullets have done just fine.

Now I understand that 1888s and 1908s are not 1898s, but you might be surprised anyway!
Regards, Joe

You can lead a man to logic but you can't make him think. NRA Life since 1976. God bless America!