I have been reloading for as long as I can remember. I recently helped a co worker reload some rounds using my brass. Some was military some was name brand, did worry about the mixed bag as it was going to be used for plinking. However none of it would chamber in his rifle, chambered fine in both of mine. We tried changing seating depth etc. case length was in spec. Then we tried new/once fired brass that was fired in his rifle only. It worked fine, never ran into this ever, anyone else?