tldr: add something that prevents players from bypassing firearm reload animations and instantly reloading ammo
add a cooldown timer to firearms that lasts 3 seconds or something else like individual timers for specific firearms (sawnoff=3secs, deagle=2secs), that prevents players from switching weapons, and the cooldown timer resets after a player switches weapons or fires a shot. (example: fire 1 shot or switch a weapon = wait 3 seconds until you can switch weapons again)
many people use the 'switch weapons to instantly refill ammo and avoid slow reload animations' exploit. it ruins balance of the weapons, heavy damage weapons like sawn-off shotgun have longer reload times than other weapons like rifles but players just switch weapons to avoid it.
if many use the exploit it doesn't mean they like it because if you don't use it then you are at a big disadvantage.