"It meant somebody's going into a Cabela's or a Bass Pro Shop would have to wait," he said. "That was a practical issue with it."
Reh also said Beretta was concerned that, after the December massacre in Newtown, Conn., Manchin aligned himself with Sen. Chuck Schumer, "one of the most anti-gun senators in the history of the country."
"The fact that he had portrayed himself as a traditional pro-Second Amendment politician before and appeared to switch so quickly...is what caused me to second guess the credibility of his convictions," Reh said.
Beretta announced in February it was considering moving its operations elsewhere, after the Maryland General Assembly began considering an assault weapons ban.
West Virginia lawmakers soon began courting the gun maker. Secretary of Veterans Affairs Rick Thompson, who was then Speaker of the House of Delegates, sent a letter to Beretta.
Speaker Tim Miley, who was then House Judiciary Chairman, urged Gov. Earl Ray Tomblin to also reach out to the company.
"As we both know, the citizens of this great state overwhelmingly support the 2nd Amendment right to keep and bear arms," Miley said in his letter to Tomblin.
Reh said he knows West Virginia is a pro-gun state, but Manchin's actions are "an issue that we couldn't ignore."