A possibility, however the FN 5.7 pistol comes with 3 20 round magazines which given it’s controllability (low recoil) it’s not a necessity.
The ammo available to civilians is not geared towards high penetration compared to LEO and Military ammo. I don’t know what type he had though.
This is starting to make more sense for me. Until now, I couldn’t see how what was reported was even possible, especially when they were reporting that he didn’t spend time at the range or have any serious weapons training.
Now it looks like he was planning and preparing for this for a long time. With practice, I can see how he pulled off a quick reload with only one weapon to worry about.
Those bullets are nasty. Real show-stoppers. One hit and you would be down.