robkarrob
Member
The reason the mag doesn't like to feed the last round, is that some mag feed lips are just slightly wider than others. My 40 mags feed the 9mm rounds perfectly, including the last round. I purchased new 9mm mags, when I purchased a stock S&W 9mm barrel. But when I tested using the 40 mags to feed the 9mm cartridges, I found the 40 mags worked perfectly. I have seen other posts with the issue of the last round not feeding properly. Since the 9mm cartridges are slightly smaller diameter, than the 40s', I would suggest to just "slightly" narrow the feed lips width. Not too much or you might have problems with feeding the 40s'. Then test for the last round issue. I was lucky and I did not have to modify my stock 40 mag feed lips. They feed the 40 cartridges fine, and when I swap barrels to 9mm, the same mags work great with the 9mm cartridges. I have two 6 rounds mags and two 7 round mags, and they all work fine with the 9mm. Of course the 9mm mags I bought work perfectly too, but you can't load the 40 cartridges into them, as the mag width is too narrow and the cartridges drag on the sides.
Bob
Bob
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