Not bad but not the best - ProMag S&W M&P 10 Round .45 ACP Pistol Magazine

I ordered 2 M&P 45 10 rd magazines and it took over 3 weeks to get which whatever. I got them finally and was super excited but when I fit test them there was a small gap but no wiggle. Worst thing was that only 8 fit. Not to happy. I hope its that the spring is still tough but I dont know.