My XD9sc magazine has the same thing, but still shoot awesome...I´m sure it won´t be a problem.
Sounds like you got my mag spring... one of my compact mags had the full size spring in it. I guess they get mixed up at the factory sometimes...:???:I don't want to think that someone at the gun shop swapped out the longer springs in the two 13 round magazines I purchased for the shorter springs in their 10 round magazines to give them more pressure, but I will only purchase magazines directly from Springfield (or maybe it they're in a factory sealed package).