Just got back from a business trip and my new sig magazine along with 2 Blackdog magazines were waiting for me. I slipped in the sig and it was not better than the original and neither were the Blackdogs. I called customer support and the rep grabbed a 522 they had on hand and reported that there was some play in it. He said the 522 is not a combat weapon and that if I had any trouble shooting it that I should call back. I am definitely not happy with this outcome. I am not one of those overly critical type either. I may toss a video clip up on youtube if I find the time later.
The movement in my mag is not just an annoyance. When I described the issue to the Sig rep and had them listen to it click and clack over the phone they said it was not fitting as designed. I was thinking of spraying it with a spray on car undercoating to get rid of the toy guy magazine look and to tighten up clearances.
I just picked up my 522 from the FFL today. Overall it seems like it is worth the $389 shipped that I paid for it except for an extremely loose magazine. Front to back it has a 1/4" of slack and side to side there is 3/16". When I handle the gun it makes all sorts of click clack sounds as it bounces around. I called the quality control number and they say they are shipping out a new magazine. I am hoping that it turns out to be a bum magazine and not a bad lower. I do have 2 blackdog mags on order. Hopefully all goes well with those. I will update when I receive the new mags.