Kodi, sorry for any confusion I caused. The dominos in the ends of the rails have over 10 inches of wood behind them and can't blow out. I use a Japanese chisel hammer because it is easy to balance, has a rounded striking face and is usually handy. The comment was meant to imply that these dominos which can't blow out the back are tapped in with a steel faced hammer. Tapped means gently enough to let the air or glue behind the domino equalize itself.
Gary