" Blueskies" wrote in message
...

OK, more questions. What was the muzzle velocity of the .50 machine guns
used as tail guns?

Try 2912 fps or 1747 knots. Real B-17's cruised about 145 knots from the IP
to the drop point, IIRC.

This means the bullet, fired directly aft, will still have a ground speed of
1602 knots.

Rich S.