Caliber is diameter. .45 means .45" wide. Different bullets (the actual projectile) can have different lengths for a given caliber. Total cartridge length (casing + bullet) can have very slightly different lengths for a given application like .45 ACP (typical handgun), but not much since it relates to how the cartridge feeds.

Why do you ask?

I need to fix this pump that uses obsolete ceramic pistons. I had a 45 shell lying around and it fits perfectly. I was thinking if a 45 bullet was the same diameter (at its widest) as the shell, than I could use a bullet (without the shell) as a replacement piston.

But if 45s look like that 38, being a smaller diameter than the shell, it would be too loose.

You could probably use a .50AE round as a replacement. Or a .50BEO .50BMG etc.

Case ID is smaller than bullet OD...case needs to be flared.

Over all round length is 1.250 but some have gotten 1.267 to function. Bullet length is determined by power fill in case.

Way too short. I was hoping for some 3 inch military shit. I think Ill go down to McFadden and look for some brass or aluminum rod and hope to get lucky.

.454 Casual casing might work.

Ya? Ill check it out, thanks man

S&W 460 uses a .45 and is longer than 454 Casull

From the unexpected history of words. Also Guy prefers the French pronunciation of his name.

The German meaning was "thirst for blood and war"