I just started reloading again after a 30 year break. Bought a coworker's 550 to go with my ancient Rockchucker. I spent the last few evenings sorting brass and found some 9 mm cases with "steps" inside. I separated them, but I don't know anything about them. Are they a problem? Obviously with the thicker case at the bottom, they must have a lower case volume. Will this cause pressure problems? I don't intend on running my 9's particularly hot.