This page will eventually be populated with tips, tricks and information to help you along your way. 

Slingshot Band Elongation Charts
These charts are used to either find your elongation percent, or find what band length you need to achieve a certain elongation. Click on the images to enlarge. 
English units
Metric units

Slingshot Ammo Mass and Energy Table
This chart has all your common slingshot ammo dimensions and energies at various velocities.