45acp has a larger diameter
Bullet Diameter of the 10mm is 10.16 mm (0.400 in) and the .45acp Bullet Diamter is .452 in (11.5 mm) So the .45acp is the winner in Bullet Diameter. The Case Length of the 10mm is 25.20 mm (0.992 in) and the .45acp Case Length is .898 in (22.8 mm) it seems that the 10mm is the winner in Case Length.
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