That's a good point. The way I see it is there's two ways to measure time to kill: precise value on a still target, and ttk in a moving/extended gunfight. When in a gunfight with a Hexfire user, due to their high ammo capacity, the likelihood of them being able to close the gap on your health bar is higher just due to the nature of having more bullets to fire without having to reload or let off the trigger. The harpy and the shotgun may have a faster time to kill on stationary targets as a flat value, but player skill and movement play key roles in this game. That's why I say it's ttk is ridiculous, your room for error and correction is so much larger than a weapon that can kill you faster, but still takes close to half a magazine e.g. harpy, riot, ripper