I have a couple of the early production "new style" BM 10 round mags. One will hold 10 rounds, the other only 9. The one that holds 10 rounds will not strip the first round off and will jam the gun unless I download it to 9 rounds. The one that holds 9 rounds will not strip the first round off and will jam the gun unless I down load it to 8 rounds. I've tried leaving them loaded for a couple of months to "soften" the springs to no avail. Is this a problem with the early production mags?