Got a preban 16" M4(a3) upper with "DSC Chromed 1X9" on the barrel and the "T12, T10..." on upper. I was told it's FN but you know... any ideas? Thanks.

Unlikely to be FN, since only Colt make M4's for the govt.  There are anumber of non Colt M4 uppers out there with the numbers on them, made by "who the heck knows" and sold by different people. Don't think it's possible to positively identify who is making them, but so long as it fits your lower, and is of otherwise proper dimensions, don't guess it matters much.

Wish the clowns advertising them as "FN" would quit though.  The most they could be is pieces that were rough cut by the same blank manufacturer that does it for FN, but that does NOT make them FN pieces.

Yeah, I should just stop asking my local shop who makes it. I don't think he has ever said anything but FN or DPMS, heh. And even when he says DPMS under his breath he says it's all FN stuff anyway. I'm not sure if that's what hes being told or what...

Still don't have a clue who DSC is though :(