Is using a Warpriest's sacred weapon to up the damage of a sling an effective idea? I doubt I am not the first one to think of this. It just seems like the only major downside to focusing on a sling is that it only does a d4. However, with sacred weapon, the damage die can go up significantly. So, what do people think? For those who have tried it, what was your experience?
It'll take two feats to get reloading down to a free action (which is what you need to make full attacks). That's on top of the already feat-intensive ranged combat stuff. You're better off using shurikens if you want to take advantage of the sacred weapon dice.
except that shurikens have nowhere near the range.
Slings have a lot of other problems. If you're willing to devote a lot of feats you can probably make a reasonably effective character based around one though. There's even a feat which allows you to use the sling in melee.
You might want to check and see if the Ammo Drop feat would allow you to load a sling with one had as a free action when combined with Juggle Load or the Halfling Warslinger racial trait. If so you could full attack with a sling while carrying a shield and maybe be pretty decent at switching between melee and ranged attacks.
Or take a 2 level dip into juggler bard. They can wield up to three items and still have a free hand for casting. You could even TWF slings.