Originally Posted by Topshot
Maybe someone might like to chip in and explain why a bullet drifts right with a right twist barrel?
It's called "gyroscopic precession."
Precession - Wikipedia, the free encyclopedia
A well balanced bullet keeps its spin axis parallel to its trajectory. You can see this best by watching a football that's passed and spins perfectly. It noses over throughout its trajectory just like bullets do.
As the long axis of a right-hand spinning bullet keeps pointing down from the bore axis it was fire at, that causes the bullet to point to the right. Left-hand twisted bullets "precess" to the left.
Note that football has a tiny bit of spin drift, too, but it's barely noticable. You can feel and see this happen as follows. Power up your electric hand drill with a long, 3/8" bit in it. Holding the drill horizontally then quickly point the bit down. Notice the force applied that tends to make the bit point to the right. If your drill's a reversable one, change it to reverse then do this again and note which direction the bit points to.