As an avid firearm person I'm always on the lookout for a good deal. I came across a feller that wanted to sell his AR upper because it just didn't shoot well any more. I bought it and found it to be a colt Large hole front pivot pin. I proceeded to thoroughly clean it and found that there was so much carbon built at that gap at the end of the riflings; it caused the bullets to loose accuracy. I cleaned that up and now have a great shooting pre-ban upper. In hopes of scoring another great deal I contacted the fellow for the lower and no he didn't have it anymore. Oh well, when I win the lottery maybe then I will be able to afford a matching Colt lower.
More details: A1 type upper, chrome lined, milled M16 sear relief, bird cage flash hider, hand grips are round ribbed style. barrel length: i'm not sure how that is measured, it is 16in from handle to distal end of flash hider.