Tannerite (rifle targets)

Tannerite is a brand of binary explosive targets used for firearms practice and sold in kit form.^[1][2] The targets comprise a combination of oxidizers and a fuel — primarily aluminum powder — that is supplied as two separate components that are mixed by the user. The combination is relatively stable when subjected to forces less severe than a high-velocity bullet impact. A hammer blow, being dropped, or impact from a low-velocity bullet or shotgun blast will not initiate a reaction. It is also designed to be non-flammable^[3] — the reaction cannot be triggered by a burning fuse or electricity.

Because it is sold as two separate components, it can be transported and sold in many places without the legal restrictions that would otherwise apply to explosives. The term tannerite is often used to refer to the mixture itself, and other reactive targets and combination explosives are often generically referred to as tannerite.^[4][2]

Uses

Tannerite brand targets explode when shot by a high-velocity bullet. Low-velocity bullets and shotgun ammunition will not initiate a reaction.^[1]

The explosive reaction, once initiated, occurs at a very high velocity, producing a large vapor cloud and a loud report. It is marketed as a target designation that is useful for long-range target practice: the shooter does not need to walk down-range to see if the target has been hit, as the target will react and serve as a highly visible indicator.

Binary explosives like tannerite are also used in licensed business applications, including commercial blasting, product testing, and special effects.^[5]

For safety reasons, Tannerite Sports LLC recommends using no more than 2 pounds (0.91 kg) of the mixed composition at once.^[6]

Target composition and sale

Tannerite targets are sold in pre-sized quantities. The package includes a first, target container and a second container. An oxidizer composition is contained within one of the containers and a catalyst composition is contained within the other container.

The product consists of two components: a fuel mixed with a catalyst or sensitizer, and a bulk material or oxidizer. The fuel/catalyst mixture is 90% 600-mesh dark flake aluminum powder, combined with the catalyst that is a mixture of 5% 325-mesh titanium sponge and 5% 200-mesh zirconium hydride^[1] (with an earlier patent^[7] listing 5% zirconium hydroxide). The oxidizer is a mixture of 85% 200-mesh ammonium nitrate and 15% ammonium perchlorate.^[1]

United States law

In the United States, the ATF advises: "Persons manufacturing explosives for their own personal, non-business use only (e.g., personal target practice) are not required to have a Federal explosives license or permit."^[5] Various regulations govern the storage of unmixed explosives. As oxidizers and combustibles, the unmixed components still have some shipping restrictions in the United States.^[8][9]

Notable incidents

A Minnesota man was fined $2,583 and sentenced to three years' probation^[10] on charges of detonating an explosive device and unlawful possession of components for explosives after he detonated 100 lb (45 kg) of Tannerite inside the bed of a dump truck by shooting it with a rifle chambered in .50 BMG from 300 yards (270 m) away on January 14, 2008, in Red Wing, Minnesota. The man was on probation when he mixed and shot the Tannerite and was not allowed to possess firearms or explosives.^[11][12]

A 20-year-old man in Busti, New York shot 18 lb (8.2 kg) of Tannerite on January 13, 2013, that sent a particularly "loud boom" through much of southern Chautauqua County, New York and extending as far south as Pennsylvania, at least 3 miles away. Multiple other sounds of explosions were also reported in the incident. The explosive noise caused numerous phone calls to the Chautauqua County Sheriff's Office, the New York State Police, and other law enforcement in the area.^[13]

The September 2016 New York and New Jersey bombings involved improvised explosive devices that contained "a compound similar to a commercial explosive known as Tannerite",^[14] set off by a small charge of unstable hexamethylene triperoxide diamine, which served as a detonator^[14][15] for the highly stable ammonal-type secondary charge.

On April 23, 2017, an off-duty U.S. Border Patrol agent, who was shooting at Tannerite targets on state trust land south of Tucson, Arizona, accidentally ignited nearby dry brush, setting off the 46,000-acre Sawmill Fire. At the time, winds were gusting up to 40 miles an hour and the National Weather Service had issued a fire watch in the area. By the time the wildfire was mostly contained one week later, it had jumped over the Santa Rita Mountains and crossed Arizona Highway 83, spreading into the historic Empire Ranch and the surrounding 42,000-acre Las Cienegas National Conservation Area. The estimated damage caused by the blaze was $8.19 million dollars.^[16] The agent pleaded guilty to a misdemeanor charge, and was ordered to pay $220,000 in restitution.^[17]

References