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1T. A. Roster, 1190 Lynnewood Boulevard, Klamath Falls, Oregon 97601, USA.
targeted birds with lead shot, and 15.5% and 13.9% with #7 and
#6 steel shot, respectively. Hunters missed birds at the rate of
65% with lead shot, and 60.5% and 63.6% with #7 and #6 steel
shot, respectively. Pierce et al. (2014) concluded that “... (shot)
patterndensitybecomes theprimary factor influencingammunition
performance”, and this factor is controlled by the shooter.
Steel Shot Lethality Tables have been compiled by T. Roster 1 of
the (then) US Co-operative Nontoxic Shot Education Program
(CONSEP). These data are invaluable for hunters to gain
proficiency in the use of steel shot. The critical point of the tables
is emphasizing shootingwithin the effective range of the shotgun
cartridge at which pattern shot density and pellet energy are,
together, capableof producingoutright kills. Itwouldbeadvisable
to reproduce the same tables in UK hunter information packages.
Insummary, cripplingof birds is related to the shooter rather than
the ammunition, and the evidence suggests that while shooters
may need to adapt to using different ammunition, steel shot
can be used as effectively, without increased wounding of birds.
Does non-toxic shot deform in
the animal’s body like lead shot?
The lethality of gunshot is not a function of its ability to
“mushroom” in the body. This is a common confusion with
expanding rifle ammunition. Soft lead pellets that hit large
bones in animals’ may lose their round shape, often fragment,
and remain in the carcass. The lethality of shotgun shot relates
to the number of pellets that penetrate the vital regions of the
animal andcause tissuedisruption. It is accepted that aminimum
of five pellets hitting the vital regions are required to produce
rapid humane kills (Garwood 1994), i.e. it is the pattern density of
shot rather than the energy in a given shot that defines lethality
(Pierce et al. 2014).
Very soft pellets that may deform during passage along the gun
barrel also contribute to poorer quality patterns. Gunshot makers
will use up to 6% antimony to harden the shot to ensure that lead
shot does not get hit out of roundness during firing and fly away
fromthemainshotpatternandnotcontributetotheshotpattern’s
density. Another process involves plating lead shot with nickel to
harden the pellet surface, prevent deformation, and generate
better killing patterns at distant ranges. Steel shot patterns well
because of its relative hardness, and if delivered accurately, kills
effectively frommultiple hits without the need of deformation.
Are lead-free shotgun cartridges
made in a broad range of gauges
and shot sizes?
Manufacturers in Europe make and distribute cartridges
according to hunters’ demands, which, in turn, are driven
by regulations. Given that the main requirement is currently
for wetland shooting, the main types of lead-free cartridges
produced are suited for this type of shooting (i.e. 12 gauge
cartridges in shot size US #5 and larger). If regulations were in
place requiring hunters to use lead-free shot for upland game
shooting, industry would make and distribute them for this
purpose. Pressure constraints prevent steel shot being loaded
into cartridges smaller than 20 gauge. Cartridges containing
steel, Tungsten Matrix, and Bismuth-tin shot are already made
in 12 gauge 2.5, 2.75, and 3.0 inch, and 20 gauge 2.75 and 3.0
inch cartridges but at production levels consistent with current
market demand. Cartridges in 16 ga and 28 ga and .410 bore can
be made easily with Tungsten Matrix or Bismuth-tin shot, but a
strong reliablemarket is required tomake themwidely available.
Can gun barrels be damaged by
using lead shot substitutes?
Barrels comprise three regions: the chamber, the barrel bore,
and the terminal choke. Steel shot is much harder than lead
shot and does not deform during the initial detonation in the
cartridge chamber, unlike soft lead pellets. There is no damage
to the chamber because the pellets are still inside the cartridge
case. As steel pellets travel down the barrel, they are contained
inside a protective cup that prevents the pellets contacting
the walls of the barrel. The only point along the barrel where
some risk might arise is when the steel shot pass through the
choke. The chokes of different makes of shotguns are not made
in a consistent, uniform manner. Concerns pertain to abruptly-
developed, as opposed to progressively-developed, chokes
in barrels. It is possible that large steel shot (larger than US #4
steel, 3.5mmdiameter) passing through an abruptly developed,
tightly- choked (full and extra-full), barrel could cause a small
ring bulge to appear, simply because the steel shot do not
deform when passing through the constriction. This does not
occur if the barrels are more openly choked, such as “modified”
or “improved cylinder”. This is the essence of the concerns. Ring
bulges are also known to occur in shotgun barrels when large
hard lead shot are fired through tight chokes. A gun barrel with a
Key questions and responses regarding transition to use of lead-free ammunition