[Jeff Higgins]

When a bullet "goes to sleep" it has started spinning about its longitudinal axis, just as we would expect it to from a rifled barrel. Prior to that, it is spinning about a secondary axis of revolution, or wobbling. Picture the difference between a quarterback throwing a perfect spiral and throwing a wobbly one. Bullets do the same thing. "Going to sleep" is when this secondary revolution stops; it quits wobbling. Lots of things affect when this happens; rifling twist, velocity, bullet weight and shape, atmospheric conditions, etc. Muzzle blast does not. The expanding gasses behind the bullet decellerate so rapidly when they hit the atmosphere in front of the muzzle that they have no affect whatsoever. This secondary revolution does have a dramatic affect on a bullet's ballistic coefficient, so until it "goes to sleep", we do indeed see a greater affect from any gust of wind.

Yes, the same gust of wind affects the bullet at all ranges. It's just that the affect is more pronounced at longer range. Whatever deviation from the intended line of flight that was imparted at 100 to 200 yards, before it "went to sleep", will carry on for the entire flight of the bullet. Plus, unless the wind dies right when the bullet "goes to sleep", it will continue to affect its flight. It is amazing just how much affect wind will have at long range; far more than one would expect.

I have seen guys run out of windage adjustment in their scopes or iron sights at 1,000 yards. My match rifles have 40 minutes of windage available on the rear sight. That is 400 inches, or 33 some odd feet at 1,000 yards. I have run out of adjustment on the rear at times. That's why I also have windage adjustment on the front sight. Now imagine needing that much say, left windage on one shot, then the wind dies or changes direction for the next. And that's just a side wind. Head and tail winds affect elevation, just not as much. Wind doping, both your own, and that of a good spotter, is critical at that range. Like I said, lots of guys crawl home with their tails between their legs after their first day. On gusty days, it's not unusual to see guys use up their ammo and never consistantly get on paper. And that paper is ten feet square...

Clearly, anything we can do to minimize wind drift will make it easier. This is where bullet weight and the attendant high ballistic coefficient is our friend. Any given cartridge in any given gun is constrained regarding how much energy it can produce by powder capacity and allowable pressure upon firing. It will shoot a light for caliber or a heavy for caliber bullet with about equal muzzle energy. The lighter one is simply going faster. Intuitively, we would think it would be the better choice for less wind drift. It spends less time in flight, so therefore the wind has less time to act on it, right? Not exactly...

Wind drift is a function of deceleration. Deceleration is a function of ballistic coefficient. Heavier bullets have a higher ballistic coefficient, and decelerate less. They are markedly less affected by wind. This would be a lot to go into in a typical PPOT sound byte, so if this interests you, check out the Handbook fo Shooters and Reloaders by P.O. Ackley and the Cast Bullet Handbook from Lyman. Both have excellent articles on exterior ballistics, complete with all of the equations you will want to see to help clarify what happens to a bullet in flight. Suffice to say here that heavier is always better, assuming your rifle has the twist rate and enough horsepower to stabilize it. That, and wind is the single biggest factor in long range shooting; a far bigger factor than most realize. Until you have tried it...

As a related aside, this is where every single movie or TV show or whatever completely falls appart when attempting to portray either some hero or villain sniper. These guys hit things at unthinkable ranges in unkown winds on the first shot. Once we are out past 300-400 yards, anyone who has tried it will laugh at the improbability of this. Wind drift on an average day gets to be several times the width of a man. Yes, we hear the real life stories like the current Afgan theater "record holder", the Canadian that dumped a guy at over 1,500 yards with his .338 Lapua. Guaranteed he had fired repeatedly at that range and, with the aid of a capable sppoter, "walked" his shots on target. He undoubtedly missed several targets before the other guy's luck ran out. This game is a lot harder to play than in the movies, kids...