Slug the bore first, but, that should be an excellent projectile for the .303 British.

IIRC - The Japanese copied the .303 cartridge, when they came up with their 'rimless' 7.7 mm Arisaka cartridge.

Check, but, possibly your '7.7 Data' is a good place to start. There is lots of data for the British cartridge.

BTW - The British copied the Japanese Arisaka bayonet, when they decided on a longer 17 inch blade "Pattern 1907" bayonet for the S.M.L.E.

(The first S.M.L.E. bayonet was the Pattern 1903 with a 12 inch blade).