advanced armament inc/colt 603 AR?

[blue109]

looking at a possible trade..guy is offering a old school AR. says its an unmarked mil-spec upper with an advanced armament lower. looks kinda funky but in a good way. cant find much info other than it seems to be early 80s vintage. anybody have any knowledge to drop on this thing? the trade value im giving up is probably only $600 so seems like im not loosing anything either way

[blue109]

update..checking out the rifle right now. ive learned more about old M16s/AR15s in the last few hours than i ever planned on knowing lol. upper is a colt 603/XM16E1. going by the ejection port cover and forend collar its an early one. probably  '64. the BCG looks to be a slighly later model but still correct for the upper. im guessing it was re-barreled because the markings dont match up, but it looks like a common barrel for retro rebuilds. the M15 lower was one of the first aftermarket (non-colt) lowers available. not rated super high for quality but not very common these days. going to put a mag through it in the morning and if it doesnt explode im going to grab it for sure. i love rails and gizmos and tacticoolness..but this thing is cool.

[MikedaddyH]

On the positive side ... If you dont like it you can always sell the lower to Drew or Matt for $600...LMAO

[blue109]

lol..now taking bids from those poor souls in communist run states....ran 3 quick mags through it after work today. no problems. smooth as buttah.