There's always this thought that muskets were really inaccurate and slow. I looked at some vids of re-enactments that showed a) musket aren't really that inaccurate when firing into a row of men, and b) reloading the baker rifle wasn't that slow. The lethality at range is also tested. Bearing in mind that these re-enactors are hobbyists, and thus don't practice every day (or probably even every week) so their quality was comparable to soldiers of the time: sorry if these have already been posted
(below clip are reenactors trying out sharpes technique of spit loading muskets)
(below clip is renactors loading and firing aimed shots with the baker rifle, 13 shots in 5 minutes)
So the musket and rifle are fairly accurate, and deadly against flesh: then you get commentary like this, in the battle of North Point near Baltimore, where 4000 american militia, and 3200 veteran British line infantry faced off, and at stages were exchanging volley fire at 20 yards:
(below clip is part of documentary on the war of 1812 - watch 9.45 for a British lieutants comment on the battle)
Yet the casualty report for the whole battle is 46 americans killed, 295 wounded, 24 British killed, 139 wounded, including casulties from artillery and sniper fire (inc General Ross). And there are accounts of grapeshot being used against British lines, and several regiments involved directly in fighting. These accounts always make me wonder what on earth went on back then.