[Ron Smith]

Something that you might check, is to see if there's a separated case stuck in the chamber. It's a long shot, but it does happen.

Here's an example. Fired a .30 shooter with a handload that I have used in every .30 that I have owned. The previous round separated ejecting the lower half of the case. The subsequent round jammed itself into the upper half that was still in the chamber. When I finally got the toggle open this came out.