Pahoo and zippy13,
I didn't think it was cylinder bore, since as zippy said, others I've had said "CYL".
I don't see any "MOD", "FULL", "IC" (or, even M, F, IMP) or anything else like I'm accustomed to seeing. I've had a lot of Remingtons and barrels and am perplexed by this one.
As for date code, I'll have to look at it again. It measure 25.5" in length. The receiver is a "V" Wingmaster receiver and it has the old lifter (pre Flex-Tab).