O it would not fit the gauge with the 4g it took some filing and tweaking and all it does is nose dive. I should have left it alone it fit the gauge with a stock basepad. Now it's junk nothing I've tried feed lip wise helps. The 140 fits the gauge and runs fine. It'll feed by hand but as soon as it goes bang it's done. Went today and in 7 rounds it nose dived 2 times. Mbx 170 and gen 2 140 ran flawless