is accuracy of Musket just Hollywood?

Rating: Null/10 (30 August 2006)

In the scene where Mel Gibsons character rescues Heath Ledger how can the muskets used be that accurate. Gibson shoots at the officer on horse back and hits him as if he was using a rifle, I didn't think that rifles were around in the French and Indian War, Gibson's guns were the ones he used in the French and Indian War right. I realize that this may be due to the director trying to make a good movie but I am not sure. Is it that the range is close enough so the musket would be accurate? These are my guesses, do you have any theories.
Thanks
Over all I did like the movie, Yes it may have been historically inaccurate, but it is entertainment, not a documentary.