Like the title says have a daniel defense s2w 16 mid length 5.56 cold hammer forged barrel. It is salt nitride coated inside and out. I got this one as an extra for a similar build. It has a 1/7 twist rate. At 750 yds I can hit a 16 steel plate with acog all day long. It is by far one of the best barrels that you can have. Brownells they list for 279.00. Im asking 220.00. If interested text matt 360-640-fivetwo03.