It appears that my magazine is not feeding correctly. When the mag is full and I insert it into the rifle with the bolt closed, I feel resistance pushing the mag to lock into position. When I operate the action quickly the first two rounds feed fine but the last two are going in at a odd angle and not seating correctly in the chamber, preventing the bolt from going to its forward-most position and closing.
I tried taking the stock off, and reattaching it with less torque on the take down screws but the problem persists.