if you are haveing trouble with accuacy your problem might not be the barrel. it is probbly the stock!
I have a bmag and the stock is in my opinion is landfill. When I shoot it I can only get relyable accuacy if I hold the stock under the barrel lug (where the barrel is screwed into the action). It seems that the stock is so flimsy that if I use a normal hold the forend twists and makes contact with the barrel.
Try a boyds stock Boyds Gunstocks
they offer a nice selection of stocks that are drop in all that is needed is for you to drop your action in.