i have a Ruger 1 chambered in 270 mag.after firing or FL or Neck sizing i can chamber these rounds PRIOR to bullet seating without any resistance whatsoever. at times i can take one of these cases that chamber eaily and seat a bullet that is NOT touching the lands and it is extremely hard to close the lever. any idea what could cause this? something is happening during bullet seating. im using rcbs dies and these rounds are only fired in this rifle.