Has anyone with an M4 ever experienced any failures to eject a spent shell when using Hornady Critical Defense rounds? My M4 has only got about 150 rounds through it, but has yet to have a problem with absolutely anything else I've tried to feed it. Various brands, 00 , #4 buck or slugs, low recoil and magnum rounds all function perfectly. The first shell would feed fine, fire, then fail to eject which caused a jam (obviously). The bolt would cycle completely, but leave the spent shell in the chamber. This would happen every other round or so. Went through 20 rounds from a few different boxes/lots, same result. I finally gave up on the Critical Defense and started using Winchester Ranger Magnum 00 Buck and 50 of them cycled perfectly. Very odd, considering my experience with Hornady ammo in various calibers has always been positive.