That was the exact same theory I had.

[img]tongue.gif[/img] Formulating a theory is one thing though, theories backed up with evidence is quite another. It just glared upon me how the numbers seem to match.
In any case... the only way to further verify this is to run an experiment on a Mac. Since I do not have a Mac, it is up to those who do.
After the Crossbows, try to do the same for normal slings with Bullets +1.
Note! Must be Bullets +1. Normal Bullets ignore STR damage bonuses.