Sure but the speed "gained" is vertical and not horizontal. Its not much you loose, but as IF is used at greater range the knietic energy delivered is lower even without considering the IF.
velocity is a vector so it does not matter to anyone that's hit what the separate components are.
There's a nice quote at the link given by Belfast of machine gun fire coming down "vertically" remember that a rifle bullet will be above 2500 ft when fired for maximum range
see this nice quote below the experiment is carried oout by
Cottesloe and his fellow experimenter H R A Mallock, Fellow of the Royal Society,
Their experiment, carried out in September 1910 and August
1911appeared to prove the maximum range of the cartridge was near 3350 yards when fired at an angle between 25 and 30 degrees, with the greatest range recorded at 25 degrees. They knew this was wrong, as both theory and subsequent tests showed the true answer was nearer 3500 yards when fired at between 30 and 33 degrees.
The problem lay with where they were testing and the calculated height reached by thebullet(see the attachment). The hills, which they originally assumed had protected thebulletduring flight from unusual wind effects were too low at 2500 feet!
Aircurrents which they could not measure had shortened the range. For more than 1100 yards of flight thebulletwas above these hills.