For anyone in the market for the M&P 15 Sport, it appears that they have changed the barrel. On another forum, two members posted that their recent purchases of the Sport came with a 1/9 twist barrel, vs. the 1/8 twist previously on the Sport. I called S&W customer support to confirm, and "Joe" advised that they have changed the spec, and that the Sport will now ship with a Melonite treated, 1/9 twist barrel. If you want the 1/8 twist barrel, you will need to purchase the M&P 15T. Still trying to confirm if it is still 5R rifling or if it is the traditional rifling.