All this hot air about bullets falling faster or slower hasn't got squat to do with suppressed or unsuppressed.
I'm amazed that all you "gun guys" posted 2 pages in this thread. (well, OK most of one was actually on topic

)
and not one of you mentioned PRESSURE.
In integrally suppressed barrels gas is bled off through holes in the barrel into the surrounding suppressor body and, by decreasing pressure will in fact keep the bullets velocity below the speed of sound.
You need special ammo to do it with a simple can on the end of a regular barrel.
Slower bullets hit lower, not higher, than the same bullet going at a faster rate.
Bullets don't all drop at the same rate. Bullet drop is a result of bullet velocity and the area of the bullet exposed to gravity.
At an upward or downward angle gravity has less effect on the bullet, there fore it drops less and unless compensated for you will always hit high when shooting up or down hill.
http://www.downrange.tv/forum/index.php?topic=18414.0