The LMT MWS .308 18" and 20" "STAINLESS STEEL 1:11.25 TWIST TACTICALLY FLAT MATTE BLACKENED BARREL ASSEMBLY" are out and available. LMT has them in stock and Questar has them on their website now. Here's a pic of a 20" from another forum. Drool....I predict a lot more over time in my immediate future.
http://www.lmtstore.com/cqb-mrp-barrel/lm308b218s.html
https://shopquestar.com/shopping65/shopexd.asp?id=1503&bc=no
http://www.lmtstore.com/cqb-mrp-barrel/lm308b218s.html
https://shopquestar.com/shopping65/shopexd.asp?id=1503&bc=no

