It is commonly agreed that on the average a bird must be hit by at least three shot, of suitable size, to ensure killing. We may say, then, that killing patterns for birds require not less than the following number of pellets within a thirty-inch circle, at maximum range:
Snipe, etc.........................350 No. 9s or $8 1/2s.
Quail.............................235 No. 8 1/2s or 8s.
Large grouse, or small ducks........165 No. 7s or 6s.
Large ducks.......................120 No. 6s or 5s.
Geese or turkeys................... 60 No. 3s or larger.
Bearing these figures in mind and glancing back, now, at our tables, we can figure pretty closely the maximum effective ranges of various chokes, in 12-gauge guns, with upland loads and duck loads. Other gauges will be considered later.
Of course, killing pattern depends not only upon choke but upon gauge of gun, since the larger the gauge, the more pellets it will handle. But let us consider one point at a time, lest our minds wander and we confuse ourselves. Some guns make dense patterns and yet bunch the pellets irregularly, leaving considerable spaces untouched. This fault may be due to excessive choke. At present there are few, if any, makers, who will guarantee even patterns of more than seventy per cent average. Any choke in excess of this is likely to make patchy patterns. Again, an extreme choke is prone to lead at the muzzle. As soon as lead begins to stick to the bore, the shot go to flying wilder and wilder. Hence the merit or demerit of a closely choked gun is not learned by firing a few shots at sheets of paper, but by testing it after a hundred rounds have been fired rapidly, as in trap shooting.
Gunmakers can easily bore barrels that will average seventy-five per cent for five test shots, yet it is only once in a blue moon that we find an arm that will keep this up in an all-day shoot, without frequent doctoring. Quite recently the eighty per cent gun has been announced. I feel like predicting that steady averages of over seventy per cent will not be attained by peculiar boring of the muzzle, but by improved ammunition and better chambering.
The shape of the cone, directly in front of the cartridge chamber, affects pattern, and so does the fit of shell. When the crimp is blown out of a paper shell, it must fit the cone smoothly and fill it, or there will be a jump and tilting of the wad. If the shell be too short for the chamber, or the cone too long, gas will escape ahead of the shot and will scatter the charge.
Cheap guns of full choke are likely to give patchy patterns, because they have not been retouched by the gun-maker after testing. If one must put up with a cheap gun, it is wise for him to select a half choke (I am speaking of 12-gauges), because what it lacks in closeness of pattern will be more than made up in evenness and uniformity of shooting.
A dirty, or leaded, or rusted bore is sure to sprinkle its charge; it may even ball some of the shot—weld them together into an irregular mass that will fly anywhere except where it is wanted. Balled shot account for many distressing accidents, where men have been injured at extraordinary distances, or when standing far out of the line of fire. They also explain how Epiphalet Snooks killed an eagle at one hundred and five measured yards, with number six shot, from grandad's muzzle-loader. He might have done the same thing with both eyes shut and while flinching out of his skin. And yet Epiphalet will brag about that gun to the end of his days and wilt have several fights for its dear sake.
Balling of shot may be caused by bad ammunition, or by a charge that does not fit the gun in hand. Too much powder, or wads that are not thick and springy enough have a like effect in a choke bore, whereas such a load would batter the shot and sprinkle it from a cylinder bore.
Some guns string out their shot in a thin procession, part of the pellets lagging as much as ten or fifteen feet in the rear. In such case the pattern might look all right on the target, but a fast flying bird could plunge through the charge and escape. Cylinder bores are prone to string their shot, or to make widely varying groups.
If the shot are too soft, or not spherical, or of mixed sizes, they will string and scatter badly, no matter what kind of gun they may be fired from.
It is more important that a gun should pepper the target evenly and that it should behave well all day, regardless of how hot and dry the air may be, than that it should make very close patterns when tested for a few rounds under favorable conditions.
Effective range depends not only upon how many shot hit the object, but also upon their penetration and the shock they impart. The killing power of a pellet of shot is much easier to determine than that of a rifle bullet, since shot are spherical. If shot of all sizes are fired with the same muzzle velocity, then the bigger the shot the better it will maintain speed, the farther it will range, the harder it will hit, and the deeper it will penetrate. Size of gun bore has nothing to do with this. A 28-gauge will drive any size of shot (if it chambers properly) as hard as an 8-gauge, and no harder, provided the powder charges give both loads the same muzzle velocity. Penetration depends simply upon speed and weight and hardness of pellet. A 20-gauge may drive its shot a little faster than a 12-gauge because it uses relatively more powder; or because the 12-gauge may be squib-loaded and hence cannot burn its powder properly; but size of bore is not the determining factor. Both guns can be standardized to the same initial velocity— it is all a matter of loading.
With the favorite powder charges of to-day, regardless of gauge, the maximum killing ranges of various sizes of shot, on pigeons, are about as follows:
No. 6......55 yards.
No. 7......50 yards.
No. 8......45 yards.
No. 8 1/2......40 yards.