Shotgunning

What Does It Take?

A ballistic balance of pellet size, weight, and velocity produces the most effective waterfowl loads

By Aaron Fraser Pass

What does it take to effectively bring down a duck or a goose? More importantly, how can that result be reliably repeated? It’s a simple question, and the answer is equally simple.

Shotgunners have fewer reliable assurances of ballistic performance than do riflemen. True, the same ballistic qualities pertain to both bullets and pellets, and both can be easily computed. With an aimed rifle bullet, however, almost all ballistic properties, including bullet drop, velocity, energy, and even penetration at various ranges are matters of predictable physics. Shotguns are not precisely aimed, but instead project a scattered swarm of pellets to intercept a moving target. In this process, a complex mix of both controlled and uncontrolled variables affects the actual field performance of a waterfowl load. These variables include choke, pellet size, pellet weight, velocity, range of shot, angle of bird (how exposed are its vital areas?), and of course other factors such as wind.

A shot pattern expands both laterally (spread) and in length (shot string) as it travels downrange. Within this cloud of shot, individual pellet placement is utterly random, and no given pellet or group of pellets can be precisely directed. However, if this scatter of pellets is dense enough, the sheer number of pellets defeats random positioning and can produce multiple pellet strikes to down the game. Shotguns that produce even patterns (without holes or weak spots) and loads that produce a short shot string are desirable because both factors put more pellets in a given area at a given instant. 

Each pellet has a certain amount of kinetic energy based on its mass (size/weight relationship) and its velocity. It is this energy, released into a duck or goose, that brings the bird down. Multiple pellet strikes magnify this killing power beyond the sum of the energies of individual pellets hitting the target.

Increasing individual pellet weight (at any given velocity) increases energy. Heavier pellets range farther and penetrate more deeply than lighter ones. However, fewer large pellets can be fitted into the finite space of a standard shot column. At extended range, these large pellets may become too dispersed for an effectively dense pattern (multiple pellet strikes). This is why 3- and 3 1/2-inch cartridges in 12-gauge and 10-gauge shotshells are popular with waterfowlers—these loads hold more large pellets, which equals longer effective range.

Small pellets increase the potential for more pellet strikes, and are quite effective at close range. However, they run out of energy, and thereby penetration, as range increases. Without good penetration, not much else matters.

Increasing velocity increases pellet energy (and also penetration), and high-velocity shotshells are currently very popular. However, as with pellet size, there is a point of diminishing returns. Shot load velocity is limited by the pressure the gun can handle and the recoil that the shooter can tolerate. Also, due to the poor aerodynamics of round balls, the faster you start them out, the faster they slow down. Thus, a killing power increase based on velocity alone (particularly with steel shot) does not necessarily equate to a commensurate increase in range.

This is the double standard of nontoxic pellet performance—steel shot plays by slightly different rules. Because steel shot is considerably lighter for its size than the other, heavier nontoxic pellets (Bismuth, Kent Matrix, Federal Tungsten-Iron, and Remington Hevi-Shot), it is a poorer ballistic projectile. Steel runs out of energy (and thereby range and penetration) more quickly. Conventional wisdom suggests using one size larger steel pellet to approximate the same striking energy of one of the heavier nontoxic pellets. But larger steel pellets limit the number of pellets in the load, which is another limit on effective killing range. However, steel loads are light and very amenable to a velocity boost without straining your gun or bruising your shoulder. Increased velocity noticeably improves steel shot performance within ranges appropriate to steel shot ballistics.

Four or five number 4 or 2 pellets driven deeply into a duck-sized target at 40 yards (with the heavy nontoxic pellets, number 5 and even number 6 can do this) should do the job. Forty yards is close to the practical ballistic limit of steel shot and, frankly, also close to the practical shooting-ability limit of most waterfowlers, regardless of shot material. 

Of course, bigger pellets punch out farther, but at the expense of pattern density. A single pellet (of almost any reasonable size) striking a vital area, such as the head or spine, will sometimes bring a bird down at extreme range. Ditto for a single pellet that breaks a major wing bone. However, these “golden BBs” of random chance are certainly not reliable indicators of effective shooting range.