On both targets, the top group is a 300-grain load, the bottom group a 180-grain--both fired with same sight setting. Impacts for the lightweight .44 (l.) and the all-steel .44 differ by more than six inches at just 25 yards.

Among shooters it is generally known that fast, lightweight bullets have flatter trajectories than slower, heavier bullets. They don't drop as much before they reach the same distant target. This is due to fact their higher initial velocity allows them to reach the target more quickly than slower bullets, so that gravity has less time to pull them down, and also because lighter bullets typically have more streamlined design, which allows them fly more efficiently with less susceptibility to air resistance than heavier bullets, which are typically more blunt-nosed and less aerodynamic.

Now when a rifle shooter zeroes his gun to be dead on, say, at 150 yards with a fast light-bullet load, and then shoots it at the same target with a slower heavy-bullet load, the heavier load will hit lower on the target. But now consider a handgunner who has sighted his .357 Magnum revolver to be dead-on at 50 feet or 25 yards with fast 110-grain JHP ammunition and then shoots it at the same target with a heavier, slower-velocity 158-grain or 180-grain load and discovers the heavier load actually hits higher on the target instead of lower.

Huh? That can't be right. It's slower, so it should be lower, right? What's making this happen? The answer, in a word, is recoil.

Recoil begins at the instant the cartridge propellant begins to ignite, generating energy that simultaneously pushes backward against the gun in the shooter's grasp and pushes the bullet down the bore. Recoil begins before the bullet leaves the bore, and the gun is therefore already moving backward in recoil while the bullet is still in the bore.

Heavy-bullet loads typically generate more recoil energy than light-bullet loads, meaning there is more muzzle rise before the bullet leaves the bore with a heavy-bullet load than with a light-bullet load, so the muzzle is pointing at a more upward angle at the moment of exit with the heavy-bullet load.

This is why, with conventional handguns fired at conventional handgun distances, heavy-bullet loads typically hit higher than light-bullet loads when fired from the same gun at the same target. Actually, there is a "crossover point" somewhere downrange where the effects of gravity and air resistance counteract the recoil effect and begin to pull the heavier bullet's trajectory below the faster, "flatter-shooting" bullet. But with conventional handguns at ranges closer than 50 yards, this is not usually observable.

The phenomenon is technically termed "bore-transit recoil" (or "in-barrel recoil"), and it can have significant and sometimes disconcerting effects for handgunners using many of today's popular sporting and personal-defense pistols and revolvers. There are a lot of interacting variables.

Shorter-barrel guns have less bore-transit recoil, although the extra weight of the longer gun may moderate the muzzle rise, resulting in similar points of impact.

It is important to understand that the practical, real-world effects of bore-transit recoil for a handgun shooter have little to do with a cartridge's absolute recoil energy, which is mathematically calculated via a complex formula involving the projectile's mass times its velocity added to the mass of the escaping gases, burnt propellant, unburnt propellant and other gases, times their respective velocities.

The absolute recoil energy of a cartridge is the same whether it is fired in a 15-pound benchrest rifle or a 15-ounce ultra-lightweight pocket pistol. For the handgunner, the important thing is rather how his gun reacts to this energy during the time the bullet is moving down the bore--and how he reacts to his gun's reaction.

In terms of the gun, the amount of muzzle movement during bore-transit recoil is determined primarily by bullet mass, bullet velocity, gun weight, barrel length and the rifling twist rate and direction. The mass of the bullet determines its inertial resistance to being moved forward down the bore; bullets with greater mass take longer to get started and are therefore in the bore longer, giving the muzzle more time to move.