+1 Mighty Sling

Like all +1 weapons, the DM will add +1 to the AC hit when using this weapon but the damage bonus has already been factored into the damage wheel.

This weapon’s damage is augmented by the wielder’s Strength bonus. For every two points of Strength above 10, add +1 to the damage dealt. (E.g., 12 STR = +1 Damage, 14 STR = +2 Damage, 16 STR = +3 Damage, etc.) If you’d prefer that expressed as a formula, use this:
(S-10)/2=B
S=total Strength; B=Strength Bonus.
Don’t forget to round down.

Strength does not affect this weapon’s To Hit bonus, only Damage is altered