[steppenwolffe]

AKs are more reliable functionally, but are less accurate and have less impressive terminal ballistics

I always thought the AK74 utilized the 223, or facsimile.

[BushMeister]

The Ak-74 fires a round fairly similar to the 5.56mm.

Here's a link to photos:

AK74

Here'a a study about terminal ballitsics:

AK74performance

[Fred Hayek]

AK74 uses a 5.45mm round, the M16/AR15 uses a 5.56mm round