Cone : Spread size (accuracy). HSM : Headshot multiplier. First column is Max Headshot multiplier, Second column is Minimum (for the few guns with Headshot fall off). Gauss Rifle can't really be measured (before anyone says anything). The code in the lua doesn't really make sense of the behavior to me personally unless the explosion happens twice. Also, by default arms and legs only take 55% damage. Keep that in mind.
In the context you gave it just sounded like a basic T weapon, that's the problem. I forgot it was in the T menu, but it is ultimately an event weapon so I shouldn't even have it on the list. Just 2 lazy 2 edit.
i'm curious as to how big in reality the ''100% damage'' area is, because honestly, ive never seen the M4A4 do the full 20dmg per shot, but instead some crappy 10dmg per shot. Also 90% of my rifleshots that arent headshots seem to do like 19dmg.
You can prob's get it in excel format from here: https://docs.google.com/spreadsheets/d/10oT2gLOJUo-3aieBxjFjwUMHUX8AcNRB-IRj60ywHhQ/