Instructor’s Rifle Practice Shots Ignited 180-Acre Fire : Blaze: Firearms class tried to put out flames before running to a restaurant to call for help.

Investigators on Monday said a firearms instructor accidentally set off the brush fire that blackened 180 acres Sunday, but said they would seek reimbursement rather than criminal charges.

Thomas N. Johnston, 45, of Anaheim told investigators that he was teaching eight people to shoot, with the permission of a private landowner, when the fire started at about 3:30 p.m.

Instead of firing pistols, as was his custom, Johnson switched to a hunting rifle and shot at a metal target on a hillside, Orange County Fire Capt. Dan Young said.

On the third round, Young said, the shot set off sparks that ignited the fire. Class members tried to extinguish the blaze on the property, which adjoins the Cleveland National Forest. When they couldn’t, they ran to Cook’s Corner, a restaurant-bar at Live Oak Canyon and Santiago Canyon roads, where they placed one of the first 911 calls to firefighters.

“He’s been pretty upfront with it,” Young said of Johnston.

“We are accepting his story and will probably not pursue criminal charges. But we will be looking for reimbursement, “ Young said, in the range of several hundred thousand dollars.

As fire officials wrapped up their investigation, pick-and-shovel crews combed the steep hillsides Monday, and helicopters doused lingering hot spots.

Hundreds of firefighters had battled the blaze, which was contained by 6 a.m. and extinguished by Monday night. No injuries were reported and no houses were damaged.

The fire broke out in a gully about a mile from Cook’s Corner. Gentle ocean winds pushed it north away from homes and into the Cleveland National Forest, where rugged terrain made it especially difficult for firefighters on the ground. Smoke was visible for 15 miles.

Fire officials said the blaze is another indication that the fire season could be especially bad.

“It’s August, approaching September,” Young said. “Next month, we’ll have Santa Ana winds. . . . A simple thing like firing a rifle can cause the loss of an entire community. . . . This person did not mean to start a fire, but it happened. We’re living in the middle of a tinderbox.”

Rich Witesman, the Orange County Fire department’s division chief for South County, agrees. “Our burning conditions are a couple of months ahead of where they ought to be,” he said. “It’s real dry. This is the kind of fire we have in September and October with wind on it. Fortunately, we didn’t have wind on it.”

But officials also said it was a chance to use the county’s new water-bombing helicopter, leased in June. The helicopter and two other choppers borrowed from other fire agencies dropped dozens of loads of water and later were joined by five tanker planes dumping chemical flame retardant.

“This is steep terrain, hard to access,” said Kathleen Cha, a spokeswoman for the Orange County Fire Department. “It’s fought in the air, then on ground.”

The Orange County Fire Department was aided by firefighters from four other counties and numerous city fire departments in Orange County. Some 300 personnel and 61 fire engines joined the battle at the peak of the effort, Cha said.

The fire crept to within one-eighth of a mile of several homes, but no one was forced to evacuate. Engines and strike teams were kept on hand to guard the neighborhood overnight.

Business was back to normal Monday at Cook’s Corner, where the Sunday afternoon clientele had watched the fire approach and then recede less than a mile away. The closure of several nearby roads spoiled the Sunday night country-Western dance party because the band couldn’t get through, owner Frank de Luna said.

“Now we’re getting more business from the firefighters buying lunch,” de Luna said.