Of course, the characters in the movie are firing with smooth-bore muskets. Most were not even equipped with gunsights, as it was an exercise in futility
I shoot regularly with a group of men who use smoothbore flintlocks. They can hit what they want out to 125yds without a problem with great regularity
Also 15-25 yds with a flintlock/caplock pistol and hitting a knockdown squirrel target 6 out of 6 times is not uncommon for the guys who practice.
These guys are hobbyists, having to depend on your weapons for your life helps you be dedicated in your practice. Colonists HAD to be good.
I've heard National Park Rangers give the effective range of the Brown Bess (standard British musket of the American Revolution and the Napoleonic Wars) has being 40 yards. I've also heard of testing by the British army which claimed that a man-sized target could be hit with some regularity at 100 yards.
I've never fired a smoothbore musket and defer to your experience, but it is important to give a little more information regarding the target size.