Speed of sound can be generalized by less than 1000 fps. It is determined by atmospheric pressure/density/altitude.
Most go for around 900 fps. Velocity is the only determination for round.
"Peace is that brief, glorious moment in history when everybody stands around reloading". Anonymous
Earp: Not everyone who knows you hates you.
DOC: I know it ain't always easy bein' my friend....but I'll BE THERE when you need me.