Hardly scientific my friend and so we'll agree to disagree on this. This is an interesting read that outlines that the transonic range has signficant impact on the stability of projectiles unless otherwise compensated.
http://en.wikipedia.org/wiki/External_ballistics
The transonic problem:
When the velocity of a rifle bullet fired at supersonic muzzle velocity approaches the speed of sound it enters the transonic region (about Mach 1.2–0.8). In the transonic region, the centre of pressure (CP) of most bullets shifts forward as the bullet decelerates. That CP shift affects the (dynamic) stability of the bullet. If the bullet is not well stabilized, it can not remain pointing forward through the transonic region (the bullets starts to exhibit an unwanted precession or coning motion that, if not damped out, can eventually end in uncontrollable tumbling along the length axis). However, even if the bullet has sufficient stability (static and dynamic) to be able to fly through the transonic region and stays pointing forward, it is still affected. The erratic and sudden CP shift and (temporary) decrease of dynamic stability can cause significant dispersion (and hence significant accuracy decay), even if the bullet's flight becomes well behaved again when it enters the subsonic region. This makes accurately predicting the ballistic behaviour of bullets in the transonic region very difficult. Further the ambient air density has a significant effect on dynamic stability during transonic transition. Though the ambient air density is a variable environmental factor, adverse transonic transition effects can be negated better by bullets traveling through less dense air, than when traveling through denser air. Because of this, marksmen normally restrict themselves to engaging targets within the supersonic range of the bullet used.[15]
15.^ Most spin stabilized projectiles that suffer from lack of dynamic stability have the problem near the speed of sound where the aerodynamic forces and moments exhibit great changes. It is less common (but possible) for bullets to display significant lack of dynamic stability at supersonic velocities. Since dynamic stability is mostly governed by transonic aerodynamics, it is very hard to predict when a projectile will have sufficient dynamic stability (these are the hardest aerodynamic coefficients to calculate accurately at the most difficult speed regime to predict (transonic)). The aerodynamic coefficients that govern dynamic stability: pitching moment, Magnus moment and the sum of the pitch and angle of attack dynamic moment coefficient (a very hard quantity to predict). In the end, there is little that modelling and simulation can do to accurately predict the level of dynamic stability that a bullet will have downrange. If a bullet has a very high or low level of dynamic stability, modelling may get the answer right. However, if a situation is borderline (dynamic stability near 0 or 2) modelling cannot be relied upon to produce the right answer. This is one of those things that have to be field tested and carefully documented.
Wind:
Wind has a range of effects, the first being the effect of making the bullet deviate to the side. From a scientific perspective, the "wind pushing on the side of the bullet" is not what causes wind drift. What causes wind drift is drag. Drag makes the bullet turn into the wind, keeping the centre of air pressure on its nose. This causes the nose to be cocked (from your perspective) into the wind, the base is cocked (from your perspective) "downwind." So, (again from your perspective), the drag is pushing the bullet downwind making bullets follow the wind.
A somewhat less obvious effect is caused by head or tailwinds. A headwind will slightly increase the relative velocity of the projectile, and increase drag and the corresponding drop. A tailwind will reduce the drag and the bullet drop. In the real world pure head or tailwinds are rare, since wind seldom is constant in force and direction and normally interacts with the terrain it is blowing over. This often makes ultra long range shooting in head or tailwind conditions difficult.
