INDIANAPOLIS — With concealed weapons now legal in all 50 states, the National Rifle Association’s focus at this week’s annual meeting is less about enacting additional state protections than on making sure the permits already issued still apply when the gun owners travel across the country. The nation’s largest gun-rights group, which officially opens its meeting of about 70,000 people Friday in Indianapolis, wants Congress to require that concealed weapons permits issued in one state be recognized everywhere, even when the local requirements differ. Advocates say the effort would eliminate a patchwork of state-specific regulations that lead to carriers unwittingly...