I know I experimented with Omens guns and mags one of the times he and I went shooting, and I found the Tan mags did not allow the slide to go forward on a full mag on insertion in any gun. From what I could determine it's because the Tan mags are stopped by the mag catch, as opposed to the mag base plate contacting the mag well at the same time as the mag catch in engaged. (does that make sense?). the Tan mags end up with about 2mm of free space between the base plate and the gun, whereas the other mags, especially the Baby Eagle ones, are touching the gun, and actually put a bit of pressure on the catch.