I think i have figured it out!!!! It apears that the front to back number Dave mentions in the video is key. Mine were mesuring 1.375-1.385. I put it in a vice and squeezed it down to 1.370, retuned the feed lips and the mag feeds 98%. So it seems that squeezing them pushes the sides out. Now the mandrel fits about 1/8" below the feed lips. A little more tuning and I should be done......now to finish the rest of my mags... Tom