I bought 3 Chip McCormick (9rd) 10mm magazines from MidwayUSA for my Dan Wesson CBOB. All of them experienced intermittent slide lock after shooting round #8. I should have just bought standard 8 round mags.

Before you ask, yes I did try different brands of ammo and the pistol functions flawlessly with the stock 9rd DW mags (actually made by CheckMate for DW). The stock mags, incidentally, feel heavier duty and have a stiffer spring.

Here is a pic of what happens. The follower rides too high and catches the slide lock. I suppose I could have bent it to work, but 10mm ammo is not cheap, and I would rather pay more and have something that works. I ordered a couple more mags from DW, and guess what they actually work.

Well, I am glad that MidwayUSA has a great return policy. Spend a little more and get a good mag.