I do not need one, but to assist a friend in building his, I (normally either .308 or handguns) ordered the parts to assemble an AR-15 in the A2 configuration.
So I guess you could call this my confession that I do go over the line once in a while. (the dark side?)
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)