No lie, that's how my dad and 2 of his buddies built fences as kids in the rocky-ass Hill Country. 6' "drive bar" and a sledgehammer makes a starter hole in the ground. Do that 20 times, every 8 feet. Cut your dynamite into 3rds, dynamite goes in holes, strung all together. Set fuse, run away. BOOM. Now you have holes for fence posts.