Quote: I just found this forum after much google searching. My main interest in slinging, is distance. I was hoping some of you other distance throwers could estimate my potential distance with the correct equipment. Here is what I am currently using: A 36" (91.5cm) long sling, from center of pouch to knot. I throw rounded beach rocks roughly the size of golf balls. I have a laser rangefinder and have measured many throws to land at a distance of 310 yards, (283 meters). What kind of improvement can be expected using a longer sling and lead shots?
Welcome Ring_Thrower!
I've punched your numbers (nice thorough report btw) and come up with the following based on a few assumptions:
- Similar shot weight - A granite "golf ball" is 46mm diameter and weighs 134g (2630kg/m^3). We'll take this to be our reference (and it is a good "standard" weight anyways)
- Same launch velocity. Using the same weight glans, this will probably be from the same sling. You might get more speed out of a longer sling, but technique and strength become factors. 36" is a good length - though many distance specialists use longer, especially true with "engineered" ammo.
- 45 deg launch. Depending on where your initial speed falls, you can often eke out more range at slightly lower angles as you can get more forward distance in the intial high speed/low drag/turbulent flow regime of the flight.
Working back from your numbers I end up with a launch velocity of
63.5 m/s, which is pretty respectable! (and realistic)
Switching to lead will pick up distance. With 63.5 m/s at 45deg, your estimated range is about
339m, a ~20% boost. Your (pure) lead sphere is around 28mm diameter.
Moving to 2:1 ellipsoid ammo gains you an extra 32m, topping you out at
371m. Dimensions are 22.4x44.9mm
The max range with no air friction is
413m, so you can see that we're getting pretty close. No need to get too fancy with depleted uranium darts etc
Here's a screenshot of my calculator with your rock and the 2:1 lead
(work in progress)
And some encouragement for you! Your calculated launch speed is right on the cusp of pulling off some pretty nice gains. As you get faster, it is easier to induce a nice turbulent boundary layer, which dramatically reduces the form drag on the projectile. If you can bump your speed by 16% up to 73.5 (fast) you'll gain 30% with the 2:1 ammo and be pushing 500m.
Matthias