Here's a series of scans that look like real letters to and from the ATF concerning an ... "unconventional" attachment for an AR-15 pistol. Might be true, the reply looks authentic. Funny, in either case. You might have to click and expand each one to read it.
I have a couple of follow-up questions about proper load data, and how many magazines of ammo, and whether Viagra would be considered cheating for the purposes of competition.
H/T to ar15.com