Joe24 said:Just scare them enough so they run to the fence and touch it. Then no need for any shooting. So no need for bullets to be transported around the country when theres really no need.
That's all very well, but you can't apply an element of fear so precisely that you can cause them to run an exact number of metres. Having worked out the correlation between amount of fear and distance run.
Furthermore, the cows might be at different positions within the field, so you would need to ensure that you not only scared them the right amount but that each one received the correct amount of fear corresponding to its distance from the fence. If that also then means that you have to fire the gun from any position other than the centre of the field, you need to take into account all sorts of other factors, such as what angle the cow will run at, any extra amount of fear the other cows will receive, and the equations just become stupidly complicated. Far easier to have a mechanism that works and kills any number of cows that run into it regardless of what velocity the cows run into it at and also isn't sacrificial.