1.5' clearance, if your pin was improperly installed. It is supposed to be a bitch to get out, hence the name "bitch pin".
Try swinging a hammer at a punch with 18 inches of play, you lose 3 with the punch, and another 6 with the hammer. Now you only have 9 inches, how much force can you get, while laying down, and going upward? Not very much.