Mine is built on a 10FP. I ordered a Shilen barrel through Northlander on the Savage Forums. Here's what I ordered:
Shilen Stainless select match, standard finish, 18”, small shank, 1 in 8 twist, threaded 1/2x28
Thread length: ¾” (Shilen charges $75 for threading)
$344 + 14 shipping
I have no problems with extraction. I usually just put my hand over the bolt and pick up the brass by hand anyways though. Sometimes it will not feed properly, and it has something to do with how I load them in the internal mag. If I carefully load them and make sure they are all straight, I can shoot 6 times without any problems. I have no experience with a 300W AR, but I can tell you that I am very happy with my bolt action. Still waiting on the suppressor to be built though.
-Dan