Theoretical BB Manufacturing...

Here is how it is typically done today for contrast.
Not sure shot balls are any more precise than bb's and the size varies more I suspect? Just guessing though.

I suspect plastic wold cool before becoming round. I think it would cool too quick prior to becoming perfectly round. Just a guess though. Plastic cools quick relative to metal if I recall. To lazy to look up material science but worth looking into.

I am not so sure a pellet shaped airsoft round would not work. Especially with a round nose. Why does the velocity need to change?

The design I have works with round BB's or not hop up at all and pellet shaped rounds, which unfortunately I need to make to test. how those work with no rifling is the question.

As far as the tower, not sure that is any better than how they make them currently or how they make metal bb's for that matter. If it works, whihc I doubt it would be cheaper than all the automated machinery.

I say you try it!

Started a separate BB vs pellet thread. Pretty sure this thread is about making plastic bb's by dropping them in water from up high.

Check for BB vs Pellet thread to keep it clean and easier to find.