"I went to class a lot of days with turkey blood on the back of my britches," Pentecost, 47, said.
As would be the story for much of his life, he had a hard time balancing his love of turkey hunting and living in the outdoors with his responsibilities at home and at work.
He spent weeks at a time living in the woods alone, following turkeys, learning their behavior and their calls.
Then in the late 1980s he started building his own turkey calls, and in 1992 made it a part-time business of his selling them out of his grandmother's garage.
Now his business, Woodhaven Custom Calls, where he and a few workers make thousands of calls of different varieties by hand, has its own plant and pays all the bills for his wife and four children.
His slate, mouth, box and tube turkey calls, sold in Bass Pro Shops and other retailers, are also getting national recognition for their unique designs, and have helped Pentecost and friends win turkey calling championships across the country.
"As a whole we are the best in the business," Pentecost said.
Pentecost won the 2008 turkey calling state championship and placed second in the National Wild Turkey Federation's Grand National Calling Contest Championships in February.
Coming in second wasn't too rough; the winner was a teammate of his who used a Woodhaven call, Pentecost said.
His son Benjamin, 9, and daughter Micah, 5, have also caught the calling bug. Benjamin won the 2008 state turkey calling championship for ages 10 and under, and Micah stole the title away from him in this year's competition.
Pentecost said what's most gratifying about taking his children to the competitions is spending time with them and watching them handle themselves in front of audiences of 1,000 or more people.
"I'm so proud of them," he said.
Benjamin said his dad promised him and his sister presents for doing their best at the competitions.
"And we won a lot of times," Benjamin said, holding out a handful of Nintendo DS games.
Micah said the competitions are fun. So is winning.
"She's been hearing turkey calls since she was in her mama's belly," Pentecost said.
Pentecost's wife Robin, who handles much of the book work at Woodhaven, didn't exactly share her husband's passion when he told her in late 1999 he was going to make turkey calls full-time.
"I told him he was crazy," she said. "Some days I still feel that way."
Robin said the job can be hectic because they only have so many resources, but she's made a lot of turkey hunting friends along the way. She said she has faith in the business with her husband at the helm.
"Anything he says he's going to do he pretty much does," she said.
Now Pentecost and the Sting Team, made up of turkey callers he met locally and around the country, are preparing for the World Championship Turkey Calling Contest in Birmingham in July.
Pentecost, who enjoys going to church and coaching Little League baseball when he's not hunting, said he has a competitive spirit that makes him not just want to produce the best turkey calls but also be the best turkey caller.
"I want at least one of those major championships," he said.