In a small bowl, combine graham cracker crumbs and butter*; set aside 2 tablespoons of mixture. Pat remaining mixture evenly onto bottom and sides of a standard 8-inch pie plate but not onto rim; refrigerate. In a medium bowl, whisk together sweetened condensed milk and lemon juice until the mixture thickens. Set aside 1/3 cup blueberries; fold remaining blueberries into condensed milk mixture; fold in whipped cream just until combined. Fill piecrust with mixture. Sprinkle reserved 2 tablespoons graham-cracker mixture around edge of filling to make a ¼ to ½ inch border. Garnish with reserved blueberries. Cover and chill at least 8 hours or overnight.
* In place of the graham crackers and butter, use a prepared 8-inch graham
cracker crust.