Shotguns loaded with birdshot (lead or
steel BBs) or slugs (solid lead projectiles specifically designed
for shotguns) are appropriate from a distance of 1
to 2 yards (1 to 2 m). Although all shotguns are lethal at
close range, the preferred gauges for euthanasia of cattle
are 20, 16, or 12. Number 6 or larger birdshot or shotgun
slugs are the best choices for euthanasia of cattle.
Birdshot begins to disperse as it leaves the end of the gun
barrel; however, if the operator stays within short range
of the intended anatomic site, the birdshot will strike the
skull as a compact bolus or mass of BBs with ballistic
characteristics on entry that are similar to a solid lead
bullet. At close range, penetration of the skull is assured
with massive destruction of brain tissue from the dispersion
of birdshot into the brain that results in immediate
loss of consciousness and rapid death.
The Canadian study cited previously evaluated
several firearms, including the .410 and 12-gauge shotguns.
The .410 loaded with either number 4 or number
6 birdshot fired from a distance of 1 meter was very effective
and had the advantage of less recoil compared with
other firearms used. The 12-gauge shotgun loaded with
number 7 1/2 birdshot fired from a distance of 2 meters from
its target was effective but considered to be more powerful
than necessary.
