Listening to someone talk about building an AR-15 or the parts required is like trying to decipher a foreign language from another planet.  Here is a list of terms you might see on the web and hear in conversation:

AW – Assault Weapon (try not to use this term. The rifle we’re building is NOT an AW)

BCG – Bolt Carrier Group

BT – Buffer Tube / Lower Receiver Extension

DZSG – Designated Zombie Survival Gun, duh

FFL – Federal Firearm Licensed dealer

LEO – Law Enforcement Officer

LPK – Lower Parts Kit

MOA – Minute of Angle.  A unit measurement used with optics. Roughly 1″ at 100 yards.  Go HERE for specifics on measuring MOA.

OLL – A California term for ‘Off the List Lower’.  What list? Check out the CA Legal post for specific details.

UPK – Upper parts kit