[SteveS]

Originally Posted by swordtart

There are inherent accuracy limitations to less advanced weapons even if the sighting mechanism were drastically improved (but see below). Hand loaded weapons are subject to variations in the quantity of powder, the quality of the powder, humidity etc. When the priming catches your view of the target is wholly obscured and if you flinch a small dot isn't going to get you back on target. If muzzle loading then forcing the projectile down the barrel can distort it such that it doesn't follow a predictable trajectory (and thus your training for drop and wind-age becomes worthless).

Muzzle loaded rifles could be remarkably accurate, with a skilled marksman:
https://en.wikipedia.org/wiki/Timothy_Murphy_(sniper)

There is also the small issue that you have to be able to see the dot to be able to use it to aim and the distance you can see a laser point with the naked eye in daylight conditions (or the thick smoke from flintlocks) won't be that far what you could use basic iron sights for anyway.

That's a stronger argument against them. But I think they would be a very advantageous tool in middle ranges, far enough that aim is useful, but not so far that weapon accuracy exceeds ability to aim.

. . . Consider that we had telescopes long before we had firearms, but the telescopic sight wasn't really practical until we had breech loading rifles. There was no point putting a telescopic sight onto a muzzle loader as you would be able to see better than you could shoot.

The problem there may have been expense rather than absence of value in aim. Short of a field test with a telescope and rifle made with 18th century optical manufacturing techniques, I'd say either argument is speculation.