The teenager is in stable condition and is expected to fully recover, says RCMP Const. Elenore Sturko.
The incident took place during a family camping trip at Little Buffalo Territorial Campground near Fort Resolution.
The weapon misfired. When the shooter tried to clear the chamber, the gun went off, hitting one of the teenager's limbs.
Police in Fort Resolution got a call shortly after midnight on July 9 from the Hay River Hospital where the youth was treated.
Thirty-one-year-old Philip Wolfe of La Crete, Alta., has been charged with careless use of a firearm, unauthorized possession of a firearm and obstruction of a peace officer.