Check the bedding and the torque on the action screws. A slightly loose or improperly torqued action screw can cause stringing. I had a Ruger which uses pressure on the barrel that was stringing. I had it bedded, action screws torqued and the barrel floated which stopped the stringing. Go up in small increments on the torque until you get to the proper setting. Remington should provide you with the proper settings.