Directly from Sig, SIGM400 Upper Receiver Kit - 16 inch, Black, Elite, 5.56 NATO (less BCG and CH), for $249 and FREE shipping. Seems like a deal to me.
https://www.sigsauer.com/store/upper-sigm400-5-56-nato-16in-blk-elite-kit-less-bolt-carrier-group.html
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