Originally Posted By FRO:
My barrel is marked differently than the one pictured above and I'm not sure its crome lined. I have an email in to the seller about that.
Overall a great upper.
Yours is the same as mine, no chrome. The proof mark by the FSB means it has been proofed, the 12 means it is not the earlier Winchester 1/14 barrel. Yours should date 1963-67 or so. FMJ3's is the next barrel in line, it is marked with C MP C meaning Colt's and proofed, the last C means chrome chamber. Later barrels had chromed chambers and bores starting in 1971, those are marked different, typical markings would be C MP B (the B meaning chrome Bore), or CHROME BORE for example.
If you asked for a three prong, like I did, your odds are much higher of getting a non chromed barrel, the chromed chamber and closed cage flash hider came out at about the same time. Am building an early rifle, and finding the properly barrel was a pain, am pleased to have gotten this upper with the correct barrel in such good shape.
Non chromed barrels were used on the Air Force Model 01 AR-15/M16, the US Army/Marines XM16E1, and the Air Force Model 02 AR-15/M16. The technology to chrome .22 cal barrels did not exist in the early 1960's, and Stoner did not think it was necessary. The chromed chambers were used on late XM16E1's, Air Force M16's, and on the M16A1. The M16A1 had chromed chamber and bore later on (1971). This is all off memory, but I got it close, refer to the Black Rifle, and Black Rifle II for specifics.
If anybody got one with the first barrel, that would be the Winchester 1/14 I would be interested in it. Those have no proof markings, or any markings of any sort.
These barrels are obviously ex-Air Force, and I am sure the seller had no idea they do not have chromed lined bores. Instead what we are getting is hard to find collectable early stuff. I just wish these came with the early bolt groups too. A couple of original style charging handles would be nice also.