Originally Posted by Amos
Why not just get a chrony that can rate joules... and fire through it with the same gun at different distances with .2 and .3?
see which one retains more energy
Because it probably would not be an accurate test. It would shed some light on the relationship between exit velocities and BB weight, but the question here I understand is measuring impact energy. Some kind of test using a kind of ballistics gel with ranged tests would probably be more a long the lines of getting the answer people want. A .20gr bb will have retain more of its energy for a far greater time than say a .42gr, weight and back spin can compensate for cross-wind interference but ultimately the added weight slows down the BB dramatically when using the same power to launch the .20gr BB.
The problem I saw with Jimski's numbers before the answers, was that he guaged a .20gr compared to a .30gr with both having the same FPS. Now for what we are looking for, that is completely off the mark on the numbers. My bolt actions for instance would launch a .20 gr BB at 450fps while the .30gr would get aprox 350 out of the same energy. So the question starts to become is the reduction in speed countered by the increase of BB weight affect the outcome of overall impact strength. But I do not believe this stops simply at the exit velocity, because as I said, the heavier round will loose its speed faster than the lighter. This is why I'd think some sort of range test with a meter that can detect and measure the impact force; done at ranges of 20ft 40ft 80ft 100ft 150ft or along those lines would be more accurate to determine which is going to be "felt more".
The reason I really don't think that exit velocity is the real way to determine this is after some years I've noticed and have been talking to another local about the "Matrix effect." This is where after time you start to notice that you start tracking and instinctively start to "avoid" BB rounds as you see them coming at you. Now I'm not talking Super Neo on the rooftop here where you're over backwards cartwheeling your arms and so on. But you are able to start tracking the heavier rounds and as such it gives you a chance to avoid the round. Lighter rounds traveling faster become harder to see and as well harder to react in time at closer distances.
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