AR-15, AK-47 & C-14 Caliber Guide: Military Rifle Specifications

Question
GCH,
I was wondering what the caliber of the AR-15, AK-47, and the C-14 rifles are.  thanks for any help you can provide me.
Chad

Answer
AR-15 in its military config is 5.56 NATO (externally identical to .223 Rem).  It can also be had in other calibers, including, but not limited to 7.62x39, 6.8 SPC, 9mm without changing the external dimensions of the gun (and in 7.62 NATO in a large package - Armalite makes one).

The AK-47 proper is chambered in 7.62x39.

There are several rifles designated C-14 (some of them fictional), so I'm not sure which one you mean.  If you are referring to the rifle used by Lee Harvey Oswald, it's chambered in 6.5mm Italian.