What part of any of the posts are not civil ? The throats on the rifles were not changed as the throat for the original P-88 ammo was 3x longer than needed for the shorter S ammo that had a bullet with a lot more taper . The chamber neck dia was checked to make sure a dirty S round would chamber easily as the S round cartridge neck was .002 larger in dia than the old P-88 . If there was already enough clearance the rifle was given the S stamp . Since most rifles as made already had .005+ clearance [ just measure a case fired in a non S marked rifle ] , they were just making sure ALL the rifles would chamber the S round . IF a tight chambered rifle was found they did ream the neck dia . BUT all of my non S and S rifles have the same size chamber necks , within specs . So that had nothing to do with pressure , just making sure the ammo would chamber in all rifles . If the bolt will close on a round in a tight neck chamber it will fire without a pressure problem . Many benchrest shooters [ including me ] shoot tight neck rifles with no problems . You have to use a little force to close the bolt , but with the tight fit you can reload the case without sizing it . Most benchrest shooters have a batch of about 25 cases that they keep reloading through out the match for each target round .