Jim has done 4 barrels for me, My 6WSM has been doing .25MOA on its last outing now that I am getting some loads dialed in. My 250AI carbine barrel has been doing 1/2MOA with a thrown together load, and my 444 Marlin Striker and 450 Bushmaster Savage barrels have both been doing MOA. The larger bores need some more load work up but still MOA with 300gr bullets is doing pretty good.

All mine so far have been on Green Mountain blanks and of course machined by Jim. Go with the Green Mountain and be happy. You might also ask Jim/Apache about the new blanks he is going to start offering. I saw on his website that he is going to start offering quality hand lapped barrels in lengths up to 32" in addition to the Green Mountain blanks. And as always he will build with any brand blank that you are willing to pay for.