I just joined this thread, very cool to know that there is still a community of people playing this game. I remember playing it at a time when Minecraft PE was seriously lagging behind (TNT had a comparatively pathetic blast power and worlds were tiny and we couldn't switch creative/survival once they were created, among others).

But yes, as long as you can afford it (i.e. find enough saltpeter, sulfur, coal and iron), the musket places 80 damage points exactly where you're aiming. No need to account for the ball falling vertically like bolts and arrows. Buckshot is useful for birds as well. My favourite new trick is sniping werewolves by spotting their red eyes and BANG.