Sorry but audio is affected by the direction of the shot, vertical angle of shot, barrel length, flash hiders or muzzle brakes, action type, powder type, bullet weight, echos, from enclosed room or not, and about 10 other factors much more than caliber/weapon model.
One does not tell the type of weapon used by some audio recorded in a phone booth.
There was audio of this event recorded in a phone booth?
And a guy on the ground would have to be looking someone in the eye. How the hell do you get a clear shot of the venue?