I was shooting my 300 RUM Sendero at the range today and noticed the bolt was starting to get sticky when cocking the firing pin. At first I thought maybe I loaded my rounds wrong and are over pressure, but noticed no other signs of excessive pressure and the impact was spot on at 300 yds. I decided to dry fire, and when I lifted the bolt, agian very sticky and it had a slight grinding feeling. I did it a couple more times and it got tougher to lift each time. The last time I couldn't lift the bolt handle until I took it home and worked at it for a while. Once I got it up, I took the bolt out. I disassembled the bolt and while looking at the cocking piece, I noticed a slight bend at the end which contacts the bolt body. Inspecting the bolt where it contacts the cocking piece, it showed signed of wear and gouging. I thought this might be the problem so I got out the Dremel and polished it smooth. Re-assembling it and working the bolt in the rifle, tt was still sticking. I now know the slight bend is rubbing against the shroud while being cocked, preventing a smooth bolt lift. The firing pin assembly is a Gre Tan drop in part to replace the J-lock firing pin factory part. When I put the old factory assembly in, the problem was no more. Has anyone had this experience before? I searched the site and found nothing covering this problem. I emailed Gre Tan and am awaiting their reply. Any suggestions would be appreciated. Thanks.