I have a stainless Rem. 700 long action (.300 Win mag) on an HS Precision stainless target barrel and target stock. I'm going to put the barreled action into a MDT TAC 21 chassis and I'd like to change the bolt (only) and find one with a Sako-type extractor. Does such an animal exist?? I realize I'd need to get it headspace again. Eric B.