I got a couple of those in last week. They do look to be a very nice barrel, as are all of DD's.
It should be noted that these are built 100% to Crane spec for the MK18, hence the 10.3" length vs. the somewhat more common 10.5".
I know my AAC would not fit this barrel when paired with a DD 9.0 Lite rail and using the older A2 style AAC mount. I had to use my phantom version to make it work. I also know that DD created a new tool in order to install the A2 and KAC flash hiders on the MK18s they build. It keys off of the slots of the hider on the inside vs. the flats on the outside as there were some interference issues with the rails as well.

