It just seems stupid to require a *whole bricksized stone* to shoot at a cricket... and deal less than none damage.
So. My suggestion is - leave it as it is, add a skill - say slingshots, and make bullets craftable
Like...
Craftable: 1 stone -> 3 bullets
Craftable: Primitive Bullet pouch (4 fibre)
max of 10.
Craftable: cloth pouch (1 cloth)
max of 15
Craftable: Leather pouch (2 leather)
max of 20
Aaaaand we're set:)