KAK 300 WSM

I know they use green mountain blanks for some of their barrels, but not sure if it's all. I have a kak 458 socom barrel with that I have been happy with. Also have a kak 300wsm bolt carrier group, but haven't bought a barrel yet. Its nicely made though.
 
Yea ive watched a couple and they worked there from what ive seen. I havent been able to find anything bad about them reoccurring and when I talked to KAK they were very nice and informative and very quick to reply so I guess ill find out here soon.
 
Anybody have real world velocity or accuracy from one of these rigs? I can find some stuff on them but not much atleast in the way of actual velocity or reliability.