PROVIDENCE — A reputed full member of the state chapter of the Hell's Angel Motorcycle Club admitted this week to firearms and drug-trafficking charges.Douglas Leedham, 54, of North Providence, pleaded guilty before U.S. District Court Judge John J. McConnell Jr. to possession of 5 grams or more of methamphetamine with intent to deliver; possession of cocaine with intent to deliver; and being a felon in possession of a firearm.