File talk:Charon Line of 3D Printable AR-15 Lower Receivers by Shanrilivan.jpg

http://imgur.com/a/2z4it#18

Proof of public Domain, note included at source link above.

And another, from the author:

http://imgur.com/a/sHGGl#0 Bellis (talk) 16:25, 30 July 2013 (UTC)