Lt. IT sounds like you may have a gas problem http://farm7.staticflickr.com/6214/6335853733_1945959e27_z.jpg Can you reference the chart here and estimate where your brass is heading? Too, there is a special tool for sorting out feed lips on these magazines if you haven't chucked the old one yet. You may be able to get some more life out of that one as a range only mag. There are a few styles out there so you'll have to google it to see if one might work better than the others for you.