By looking at the lines on the brass I would say you were FLSing. You might be bumping the shoulder back to far... or any of the other ideas. Try the cheapest and simplest things first. If you dont have a headspace measuring tool to check your cases then use some tape on the primer end of the FLR case and see how much space you have. Measure your FP hole and compare to the FP. Keep notes. Read them. It will come.