Purchased what was advertised as a new rifle thru Gunbroker. Noticed that the bolt seemed a little loose and sloppy when I worked it. Started noticing increasing pressure signs while breaking in (flattened and cratered primers - ejector marks on case head) I dropped back on loads I worked up that were well within Sierra guidelines. Made several rounds beginning with their starting load 43.7 g of h4831sc behind a 140g Sierra Game King with a c.o.a.l of 2.79 in Norma brass with CCI 200 primer. Shot only one round and the bolt stuck and had to be tapped out. When I finally for the bolt released the brass was stuck to the bolt head and the primer fell out of the case when I pulled the case away from the bolt head. One of my shooting partners thinks it's a head spacing problem. What do you guys think?