Threatened by long-term declining participation in shooting sports, the firearms industry has poured millions of dollars into a broad campaign to ensure its future by getting guns into the hands of more, and younger, children. The industry’s strategies include giving firearms, ammunition and cash to youth groups; weakening state restrictions on hunting by young children; marketing an affordable military-style rifle for “junior shooters” and sponsoring semiautomatic-handgun competitions for youths; and developing a target-shooting video game that promotes brand-name weapons, with links to the Web sites of their makers.