I have a kimber montana 270 wsm that sometimes has very difficult extraction with factory loads. I have tried federal fusion and winchester supreme accubonds and both cause the problem. Sometimes I can barely open the bolt. The brass and primers look OK afterwards. Accuracy for this gun has been marginal. It shoots 2 to 3 inch groups at 100 yards from a rest. From the same rest I can shoot 1/4 inch groups at 100 yards with my Ruger Hawkeye. Any ideas on what is going on with this rifle or should I send this rifle back to kimber?