[Samhain]

Slings are far more difficult to master than bows. I'm not sure that the -2 penalty is enough. This is why slinging is not nearly as popular today as archery.

I believe the reason that ancient slingers were so effective even relative to their bow armed contemporaries was that sling training was both far cheaper and much more accessible.

Any mother could make a battle worthy sling for her son in little time, say a lazy afternoon. The boy could then load it with stones picked from a local stream, the best of which could be passed on to his great grandson.

A bow built for warfare and each arrow it fired on the other hand required substantial investment of time and materials from likely more than one specially skilled craftsman.

As for damage, my understanding was that slings tended to fire larger projectiles and at higher velocities. Though, as the projectile was much more blunt they had lower PSI at the point of impact and, therefore, less penetration.

Further complicating the issue would be that there was arguably much more variation in sling stones than with arrows as the former could range from irregular stones shaped by river water to purpose made ceramic balls or even oblong lead projectiles that spun like a bullet in flight.

Some sources I've read also said that among some armies used stave slings almost exclusively. These two handed devices were capable of throwing much larger projectiles but were even harder to master.

I'm not sure if any of this helps. I just felt like sharing some of my research on the subject.