The Minnesota Gun Owners Political Action Committee has offered to pay for firearms training for Democratic congressman Rick Nolan at the chain of retail stores owned by the family of his Republican opponent, Stewart Mills.

The offer came in response to a picture posted to Twitter on Wednesday showing the congressman holding an AR-15 rile with his finger on the trigger while surrounded by supporters.

Bryan Strawser, executive director of the Minnesota Gun Owners PAC, said Nolan's actions were "unsafe and dangerous."

Gun rights have emerged as a key issue in the Eighth Congressional District race. Mills released a campaign ad this summer that claimed Nolan is among the politicians who "have no respect for the Second Amendment."

Nolan earned a 'F' rating The National Rifle Association's Political Victory Fund, but dismissed Mills' ad as a "big lie, smear tactic." Nolan aides said the congressman declined comment on Strawser's offer.

"The basic rules of firearms safety, taught to students as young as 12 in [Minnesota Department of Natural Resources] hunter safety classes, state clearly that one's finger should be kept off the trigger until ready to shoot," Strawser said.

"It's nothing short of hypocritical for Mr. Nolan to be photographed at what appears to be a campaign event while holding an AR-15 rifle," Strawser said. "Mr. Nolan has specifically called for a ban on the very rifle he is holding in this photograph."

The Minnesota Gun Owners PAC offered to buy firearms training for Nolan at Mills Fleet Farm Indoor Shooting location in Baxter.

It's the same shooting range where Mills, a company vice president, recorded an "open video letter" to Nolan and other Democrats in Congress, advocating for armed security in every school. He also argued against the push to pass gun control legislation in Congress, saying it "isn't about controlling guns, it's about controlling people and limiting your freedom."

The video, which has racked up more than 307,000 views on YouTube, features a live-fire demonstration at the shooting range and may have unintentionally served as the soft launch for Mills' congressional campaign. He officially entered the race five months later.

In the video, Mills notes that hunters can find an exclusive line of AR-15 sporting rifles at the location. But the political point was to challenge a Nolan assertion. During an appearance on CBS' "Face the Nation," said that "I don't need an assault rifle to shoot a duck."