6.5 284 norma fatory loads

hsm with 140 bergers shot 2850fps no pressure shot just under 1 inch 5 shot with 4 min delay between shots. The Norma factory 140 pation too hot for my gun. one roung went 2997 left ejector mark and bit of tight blot lift one went 2950 no ejector mark one went 2959 no ejector mark . Have not check pri poc yet. temp +80 my gun seems like its has tight neck bought k&m turner loaded rounds were 293.5 fired chamber went .296 could this be pressure problem first shot with new case shows no pressure but after neck bushing.292 pressure goes up enough to see ejector marks same load with any suggestion on case prep.