I was hoping that these would work for my FN SCAR 17S and my AR-10 mags. I was not disappointed. They are a perfect fit for all of them. I have SCAR mags from 3 different companies and they are a perfect fit. Same goes for my MagPul PMag20 LR/SR Gen3 mags for my AR-10. Perfect Fit, even with the dust cover on. I will be setting up another vest, so I will be placing another order for some more of these. 5 Stars all-around. Thanks.