You do not "aim" a Bess ... The drill of the period called soldiers to "Level your firelock.... Fire" nobody expected a Red Coat to aim at anything in particular !
The fact that the word "present" was the command to level the muskets at the enemy prior to firing them, does not equal evidence that muskets were not "aimed". Further the command "present" was maintained in the British army LONG after they acquired breechloading rifles.
"When powder is given to Recruits, they are to be taught to load and fire singly, that each man may be distinctly instructed in the proper methods of using a Cartridge, and be encouraged to proceed without dread or confusion ; they are then to be fired by Files, and so on by degrees, until a number of them maybe ventured together : they should be taught to fire at marks, at different distances ;
The general yearly allowance of Ball to a Regiment, when not on Service, being only four to each Man, the insufficiency of that number, for frequently practicing the Companies at firing at marks, must be very obvious ;
Leaping, running, climbing precipices, swimming, skirmishing through the wood, loading and firing in different attitudes [positions] at marks, and marching with remarkable rapidity, are the particular Exercises, to which these [Light Infantry] Companies should be trained…"
Cuthbertson, System, for the Complete Interior Management and Economy of a Battalion of Infantry published 1776
LD