The outing resulted in the Goat Fire, which would burn 73,378 acres, the Wenatchee World reported.
U.S. Forest Service officials have not said whether their investigators believe the fire was caused by the target or a bullet striking something else.
There's plenty of disagreement about whether targets that explode can start fires. Some think they're dangerous and should be banned; others say they're no danger.
But as exploding targets become more popular they are more often linked to wildfires. The devices have been blamed for starting at least two dozen fires across the West last summer, the newspaper reported.
Fire officials last summer said that two other smaller fires in north central Washington - a 120-acre blaze near Entiat and a quarter-acre fire near Cashmere - were started by people shooting at exploding targets.
Kelsey Hilderbrand, owner of High Mountain Hunting Supply in Wenatchee, sells one brand of exploding targets, Tannerite, for between $4.95 and $9 apiece.
"They're very popular, and they're a lot of fun," he said, adding that he has used them and that the targets have never started a fire.
"They are not a heat-related explosion, so there's no way to have an ignition-based system," Hilderbrand told the Wenatchee World
"There's no question they start fires," said Bill Gabbert, a former wildland firefighter and fire investigator in Southern California who produces the online magazine, Wildfire Today.
Gabbert believes they are a growing danger because more and more people are starting to use them.
"I think we need to figure out a way to ban the use of exploding target," he said, adding, "I'm convinced they are too dangerous to use."
Exploding targets are a mixture of an oxidizer - usually ammonium nitrate - and a fuel, such as aluminum.
The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives does not regulate the sale and distribution of these powder chemicals, even when they're sold as kits designed to become explosives, according to its May 2012 newsletter.
Once mixed, someone must have a federal explosives permit to transport them, the newspaper reported. Sportsmen generally mix them onsite before using them as targets.
In Washington state, exploding targets are illegal to use on state land, said Larry Raedel, chief of law enforcement for the state Department of Natural Resources.
"We don't allow any explosive or incendiary devices," he said, including Tannerite, an exploding target which, its manufacturers claim, does not ignite fires.
The question isn't so simple on federal lands.
"We don't have anything that specifically addresses explosive ammunition," said Tom Knappenberger, regional spokesman for the U.S. Forest Service.
In California, Sgt. Bob Epps, bomb squad commander for the Riverside County Sheriff's hazardous device team, said his officers are charging businesses and sportsmen for possession of these chemicals, even unmixed.
Retail stores in his county have been told they have 30 days to return their inventory of binary explosives, or they can be charged with a felony under California law that bans the devices.
"We understand that this has not been tightly regulated," he told the newspaper.
Epps said he believes the explosives could cause serious injury, although he hasn't had any incidents in his jurisdiction.
John Maclean, who has written several books on fatal wildfires, said he's concerned about the danger that exploding targets pose to firefighters.
In northeastern Pennsylvania, two game commissioners were investigating a fire caused by exploding targets when an unexploded target suddenly exploded. They checked into a local hospital with temporary blindness and hearing loss, and went back to work the next day, the Wenatchee World reported.
"It's a growing problem, and it's going to get worse," Maclean said.
Local sportsmen say the real issue should focus on whether people are acting recklessly. Hilderbrand said the issue rests with the individual responsibility of the target shooter.