Cash and carry. Brick and Mortar or the 'net.
Some 'net ammo sites do want photocopy ID and a signed statement, but that isn't CO requirement.
Raw Video: Bomb Squad Detonates Hazards In Shooters Apt (video at link)
I was unable to pull the video to post it directly
http://patdollard.com/2012/07/raw-video-bomb-squad-detonates-hazards-in-shooters-apt/