While waiting for my x-series 320 to arrive, I laid in some 17 round mags. It came w 4 21 round mags, but more is better. When I got the gun, the first thing I did was take off the magazine well flare (just didn't like the looks). The 17 round mags don't fit!!! I suppose I could trim some plastic off the mags so they would seat, but c'mon SIG - why?