Bit of a strange question I admit. I was watching Banished on the BBC earlier this year, set in Australia in 1788, and a fellow gets shot point-blank in the head by a flintlock pistol and goes into a horrendous spasm for about five minutes because the ball gets lodged in his brain instead of out-right killing him. Equally, I was watching Time Team yesterday (they were digging around a Tudor-era fortress in the Channel Islands) and they described how a piece of lead shot could kill multiple people in a row, with those behind even being wounded by bone fragments from the poor sods in front.
Gunpowder weaponry was absolutely brutal across the board, but by the sounds of it, getting shot in the head - even at long range - was the worst deal of all. If you did experience the unfortunate circumstance of getting shot by a musket, with death almost certain, which wound would provide the quickest/most painless demise?
Well, the thing is that death from a black powder ball isn't certain, in fact it's far from certain.
Unlike contemporary smokeless powder, black powder is slow burning and weak with a large portion of energy being lost from windage within a musket (windage being the spacing between the barrel of the musket and the ball). Even then, minor things such as purity of the powder and how much powder you put in the barrel (sometimes an anxious soldier can not pull the full load into the barrel due to missing the barrel and the charge falling on the ground).
Even then, black powder doesn't really have much strength with soldiers even reporting that they get at worst a welt on their skin from a weak shot. Even getting shot in the face with pellets from a shotgun doesn't kill, Marshal Massena was shot by Napoleon by accident during a botched hunting trip. However, this is standard musketry in the 18th century. Muskets back in the time of the Tudors would be bare bones and weaker due to less powerful powder, but that doesn't mean cannons might not be the source of this event of multiple people being killed in a row.
Well remember, you were watching a movie. You can be shot by a musket about anywhere and have a chance of dieing. A headshot will most likely kill you straight off, not not always. Most men who died from being shot did not die because of the bullet wound. They died from the wound getting infected pre or post-op. The worst place to be shot would be the chest or stomach. They basically proped you against a tree or fence and waited for you to die.