Re: contender with 35 rem. barrel.
Check our hinge pin to see if you have any wobble or any kind of play in it with the forearm off. Then, check to see if the forearm is making contact with the barrel. If its wood, it's and easy fix by just carefully sanding the trough until you get good clearance, then hit the sanded portion with some wood sealer. Also be sure your forearm screws are tightened to the same tension if at all possible. If that doesn't fix it, then go to your optica and/or mount and check for tightness. Good luck.
Big Al's "Take-Em" Style Silhouette Decoys Pro-Staff.