Wrinkly brass, that's the only way I can describe it and no idea of how it happens. I reloaded some 30-06 ammo recently using Remington brass (which may be the reason there depending on who you ask) and when I fired it it seems to be fine with no pressure signs. However on one side of the case about 1/4 inch above the base one side is bulged while the other side is smooth. I thought it might be due to an un-square die but I remedied that and still get the same result. Any ideas of what's going on?