HS percentage in valorant doesn't represent skill that much unlike other games. In valorant it counts HS% by headshot out of all shot and NOT headshot per kill. So if you one tap 4 person with headshot and then proceed to spray 4 bodyshot on the last guy, your HS% will be 50% even you kill 4 people with headshot and only bodyshot one person. Now imagine that with shotgun. Even you have a god aim and one tap 20 guys, 20 hs kills in a match, if you manage to get about 5 kills with shorty (or any shotgun) it can bring your HS% down to 20% (and we all know that you can't one tap 20 person without spraying a single time, even tenz has to spray sometimes)