Lead-Free Hunting

All-copper bullets are a safe and humane alternative to lead bullets for big game hunting. Mike Kemp Images/The Image Bank/Getty

The Lead Problem

Throughout modern firearms’ evolution, lead has been the material of choice in the manufacture of ammunition. The high density of lead and its deformation characteristics give it desirable ballistic properties. For hunting purposes, lead is used to make the small, round shot packed in shotgun shells, and is the main component in the bullets used in rifles.

What makes lead less than ideal, however, is that it is quite toxic. In 1991 in the United States (and in 1997 in Canada) lead shot was banned for waterfowl hunting. Up until that point, tons of lead shot had been raining on wetlands all over the continent each hunting season. As ducks were foraging for food in the sediments at the bottom of wetlands, they would ingest lead shot and many would eventually die of acute lead poisoning. Bird hunting upland, for example for pheasant, grouse, or quail, was not included in the 1991 ban. With upland hunting, the shot used does not become concentrated in discrete locations and it was not believed to be problematic to the degree waterfowl shot was.

The same might have been believed for rifle bullets, which are to this day mostly made of lead. However, there are real environmental and health hazards associated with the use of lead for any type of hunting, and many hunters are changing their habits accordingly.

How Lead Bullets Work

In hunting rifles, the lead bullet is shot at high pressure into the target. At that point the collision with the flesh of the animal deforms the bullet, turning it into a wide, flat blob, killing the animal quickly if the shot is well placed. However, there is a key problem with lead bullets: when the bullet hits its target, it looses energy by deforming and breaking up, with dozens of small lead fragments ending up lodged in the entrails and the meat of the animal. These fragments can be as small as sand grains, and they are often found over a foot from the wound channel.

Environmental Effects

When a hunter guts a large mammal, the lungs, kidneys, digestive track, and other organs are left in the field, and with them tiny lead particles. These “gut piles” are fed upon by scavengers like foxes, coyotes, ravens, red-tailed hawks, eagles, and many other birds and mammals. The small lead bits are accidentally ingested as well. A very small lead fragment in an animal’s gut will be dissolved by the digestive juices, elevating blood lead levels to several parts per million, which is enough to kill a bird as large as a bald eagle. Anyone who has been in rural areas on opening day of a deer hunt can appreciate how many gut piles are left behind in the woods and imagine how many scavengers must have elevated lead levels in their blood. 

Health Effects

Traditionally, when big game hunters butcher their quarry they carve out the meat about two inches around the entry and exit wounds. When researchers used portable x-ray equipment to look at deer carcasses killed by rifle, they found very small lead fragments far away from the bullet wounds. These fragments then end up in the meat consumed by humans. Even packaged ground venison examined with x-ray technology showed a peppering of very small lead particles, small enough to be unnoticed by the unsuspecting eater, but large enough to cause dangerous health effects.

Even at low concentrations, lead in adult humans interferes with renal function, affects learning and thinking, and disrupts our reproductive system. In children, nervous system development is impacted, and there is no such thing as a safe blood lead level. In communities getting a substantial proportion of their protein from wild meat, blood levels with significant lead levels are commonly found.

The Solution

For shotgun shells, various non-lead materials are now available for upland small game hunting, including steel, bismuth, and tungsten. For large game hunting, all-copper rifle bullets are now on the market for most calibers, and are gaining rapidly in popularity. These bullets retain their mass when entering an animal, without losing small pieces like lead does. Non-lead ballistic characteristics are very acceptable for most hunting situations, and the modern copper bullets have been field proven to be at least as lethal as conventional bullets. The only disadvantage of non-lead bullets is their cost, which is on average about 40% higher.

In 2008, California banned lead ammunition in areas where California Condors live, as lead was identified as one of the major threats to that species’ existence. The ban will be extended to the entire state by 2019.

For More Information

Web resource discussing the science: Hunting with Non-lead.

United States Geological Survey. Lead Poisoning in Wild Birds.