Do you want to shoot rocks out of your slingshot? Choosing the right bands for shooting stones is important!
Just about anyone who has shot a slingshot as a kid, probably shot rocks. They are readily available and provide a solid THUMP when they connect with the target. However, there are some important things to keep in mind when shooting rocks.
Make sure the slingshot you are using to shoot rocks with is suitable for shooting rocks with! You will want a wide fork gap. Natural fork slingshots are perfect for this!
Choose the correct bands! Not all bands are made for shooting rocks. You will need an oversize pouch for holding irregularly shaped stones and bands that don't over power the rocks in flight. When rocks fly too fast, deflection of air over their uneven surface can cause the projectile to veer in flight.
Consider the weight of the rock! Picture it this way... a 3/8" or 9.5mm steel ball is much lighter than a .374 lead ball. Even though the .374 lead ball is 9.5mm as well. Like with ball ammo, it truly depends on the density of the stones that are being shot as to what taper and thickness is best. A lighter sand stone may be fine with one taper, however, a denser stone of the same size that taper may not be enough. Even worse yet is having bands matched for one weight rock and shooting a much lighter rock with a now increased speed which is likely to cause a unintended flight path thus striking a unintended target.
If possible, walk around the area picking up stones of the like you will be shooting and then compare their weight to the recommended ammo weights for different tapers and thicknesses of latex. This is the best option for making a bandset for rocks in a particular area you visit often.
If making your own bands specifically for shooting rocks than you can always cut a wider or narrower taper. You can even do double layered bandsets with the .7mm thickness. The .7mm thickness would be fine as it is a little more versatile. You can also go with the .8mm and a narrower taper as well though. Please remember to not try and overpower rocks as it can cause you to hit unintended objects due to flight deviation.
Finally, select rocks and stones that are roughly spherical and have few sharp edges. Creek beds, beach stones, and landscaping gravel is a good choice. Be sure the stone fits inside the pouch completely! Remember stones hitting bands and rubbing the latex on their way thru the fork can cause band failure to occur quite rapidly. Be sure to keep a eye on bandset wear.