I have been getting emails and IMs asking about the source of the 1/7 retro barrel. Lionel Lin, AKA Boywonder777 on Gunbroker and AR15.com had a bunch (about 20 units) made up by John Thomas (master retro-smith) of RetroArmsWorks.com .
They are new CMMG 20" 1/7" twist A1 profile pencil barrels, Colt M16A1 FSB and sight, Colt M16birdcage flash hider and correct split washer, a flat slip ring group (with weld spring, and snap ring, and barrel nut). Demill handguards, that need repair, are available. They also come with Colt M16 gas tube and roll pin. He still has some. He sells for $275 Buy it now on Gunbroker. I have been dealing with Lionel for years, and he is a straight up guy, and a first class vendor. I get nothing from this plug, but know that a lot of you guys like retros but don't want 1/12 barrels, or even 1/9! He also sells lots of other retro AR and standard AR parts.
His email is: iams0b3@gmail.com