Tom Selleck is stepping down from the National Rifle Association's board of directors, his publicist confirmed to USA TODAY.

The "Blue Bloods" star, one of the NRA's most famous celebrity supporters, has been a member of the board since 2005 and was re-elected to his fifth three-year term last year. He first joined the organization at age 8.

According to the website for the group's National Firearms Museum, Selleck has donated 11 guns, including several used as props in his 2003 film "Monte Walsh."

Selleck, 73, also appeared in print advertisements for the NRA, including a controversial one in 1999 where he posed with a rifle over his shoulder accompanied by the slogan, "Shooting teaches young people good things." It drew criticism for its timing, which came a month following the massacre at Columbine High School.

His publicist, Annett Wolf, referred USA TODAY to the statement she gave to The Trace, an online publication dedicated to gun-related news, where she said Selleck was stepping down due to his work schedule, but would remain a member.

When asked by USA TODAY about projects Selleck is currently working on, Wolf cited "Blue Bloods," the CBS police drama in which he plays NYPD police commissioner and father Frank Reagan. It returns for its ninth season on Sept. 28 (10 EDT/PDT).

“He has nothing to do with policy," Wolf continued in her statement. "He’s never been active on the board or anything the NRA engages in. He’s almost always been a silent board member.”