slingshot vs flint lock /cap and ball pistol....

[Murray 3-D]

What would you rather be hit by, a 50 cal lead ball traveling 1500 fps, or a 50 cal steel ball traveling 200 fps?

This.

 

[Murray 3-D]

A flintlock smooth bore isnt restricted to single lead balls either. U can drop a hackysack of shot down the bore in seconds which basically turns it into a open choke shotgun. Lead shot out of a shotgun is going to mess an enemy up more then a sling shot projectile IMO.
And reloading that only takes a dozen seconds. Pistols probably can load even faster.

 

[Chumlee Bumsnag]

What would you rather be hit by, a 50 cal lead ball traveling 1500 fps, or a 50 cal steel ball traveling 200 fps?

Yup. This.