The Sportsman Guide has Bergara 30 caliber barrel blanks for sale. The are 18.2" or 16.35" long, 1.13" diameter. .308 bore.
The price is $44.97 for a member, $49.97 for non-member.
My Encore Bergara barrels has shot MOA so hopefully these would be of a decent quality.
4140 steel in the white, no chamber, no threads.