you bought ammo, rounds, cartridges....
bullets are just the projectile.
just like the thing that holds the rounds is a magazine and not a clip.
Clips are real, but they either load magazines(removable or internal magazines) or hold rounds en bloc for specific firearms like the M1 Garand.
btw I have the MK II which is basically the MK III but without the lawyer generated ‘inprovements’...
Well, I bought 500 of those things that go boooom! Reminds me of when I was in the army:
This is my rifle
This is my gun
This is for shooting
This is for fun