Yes....and No.
I've got my university level physics just like anyone else, and if we really want to go there...we can, but rifling and spin, at very short range, doesn't impart any "accuracy" benefit to a musket ball.
I put accuracy in brackets, because when the layman talks about accuracy, he really often means precision instead.
So.... lets get into it then.
The baseball analogy is inapplicable, to our situation. Baseballs aren't spheres, they're lumpy spheres because of the stitching, and it's the uneven and
unpredictable airflow over the surface of the ball which causes the erratic motion. This effect is serious, because the angular rate of movement is very fast compared to the linear rate of movement, because the ball has a relatively large diameter (surface area of 27 square inches), and spins quickly, the ball is thrown relatively slowly, at most, 160 feet per second. It's also easy to move a baseball around because it's just not that dense, in comparison to the large surface are it has.
If a baseball was made of lead or steel.....any spin a pitcher could impart wouldn't really alter trajectory over sixty paces.
The fastball isn't "accurate" because it's spun, it flies to the same point of impact because the pitcher holds it at the same place, and puts the same spin on it every time. If he doesn't put the same spin on it, then it won't impact in the same place.
Now, a musket ball would be no more accurate (technically, precise, as opposed to accurate) if spun, than not spun at all, but random spin, will put a musket ball off point of aim slightly due to the magnus effect.
But since the musket ball is almost a perfect sphere, has a small diameter and therefore a very small surface area(0.7 square inches), and the distance we're talking about, (40 paces) is negligible in relation to the linear velocity, and the density of the projectile is vastly greater, spin is just not going to come into play.
The magnus effect is just not going to be able to move the point of impact of the small, smooth, dense ball at forty paces, in air, unless you were able to impart ungodly fast, and random rates of spin.
*** If you want, we can continue this, and get into the math over at the sciencemadness forum, and have good peer oversight. I used to be a regular there when I was a pure sciences major, and there's alot of clever fellows who can catch any mistakes we might make.***