One of the many problems I experienced on my old factory refurbished MK-40 elite98 was magazine droppage during firing. At first, Kahr sent me a couple of more powerful catch springs which sort of helped, but not really. Finally they sent me a new catch with a cut-out shelf to go in to the cut-out of the magazines. The old design had a sort of bulge which pressed crudely into the gap, but did not have a geometric ledge to completely prevent the mag from coming out without hitting the the mag release button. Now the problem is fixed, however due to the cut-out in the catch, the mag now sits a hair lower than before and rattles. It is not good for CCW purposes (noise-wise), but it has not caused any malfunctions yet and that includes no more mags dropping during firing.