Why are there so many gun models using the same calibre? Doesn’t the bullet determine most of the lethality and range, while the gun is just the vehicle that fires it?

Question

Why are there so many gun models using the same calibre? Doesn’t the bullet determine most of the lethality and range, while the gun is just the vehicle that fires it?

In: Physics

Answer 1

I feel like this is similar to golf clubs. Ball stays relatively the same, and the clubs are the vehicle with which to whack. Branding and slight variances aside, all clubs are just metal sticks.