On occassion my mag partially drops while firing thereby preventing the next trigger pull. I filed down the mag release button so I am pretty sure that my grip is not causing it. In addition to the two factory mags I purchased two used ones. Not sure at this point whether which of the mags may be the culprit. I've attached a photo of the two different types. I can see a difference only where the mag holder clicks in. You'll notice that the upper one in the picture had the bridge piece between the two square notches slightly indented, whereas the the lower one's bridge is level with the magazine edge. The lower one that is level has a warning on the mag side that says "Caution - capable of firing with magazine removed." Both have the S&W logo so they're OEM. Since my model has a disconnector I assume these are the used ones I purchased. Any input on solving my mag drops will be appreciated.