So, a person born in that world (with magic power naturally in their body) who is trained enough can "see" the trajectory and the actual bullet of a .45 cal handgun and thus swat the thing out of midair or evade it. However, they can't keep up with a bolt-action rifle's bullet because it was too fast and too small. That would mean MC needs to make guns that use rifle-type rounds like the Five-Seven handgun, super high-caliber revolvers, or assault rifles if he wants to make guns an actual advantage.