timothyausten wrote on Dec 3^rd, 2024 at 1:28pm:

Hmmm...........where to find an 8 kg stone??? 

I started looking at cannon balls on ebay. 

Kind of expensive, but not too crazy.  I think I might give it a go.  It will need to wait a little while though.  I hurt my left arm moving my target around and it still needs some healing time.  I'll definitely need two good arms for handling that weight.  I'd prefer the weather be a little warmer too.  So maybe in the spring.

These comparisons are eyecatching, but I would question their usefulness. As a relatively large man at full sprint I can exceed the kinetic energy of a .44 round.

Ke = 1/2 mv^2 = 1/2 * 110 * (5m/s)^2 = 1375J

Yet a rugby tackle from me would obviously not be as lethal as a 44 round. Not even as much as a 22 round which is far lower energy (and probably a better comparison of the type of energies that can be generated with a sling generally).

With bullets we have to consider the lethality of a small dense object effectively focusing that energy to a small area. The pressure that can be created at impact point is enough to tear holes through flesh which can have lethal effects. Huge slingstones cannot generate that kind of pressure and cannot kill via that mechanism. It's really comparing apples and oranges at this stage.