The line of reasoning that 0.05g shoudn't make much difference is silly. Yes, 0.05g wouldn't make any sort of difference for the items the size of what we manipulate in our lives daily. However, for a 0.20g BB that's a 25% difference in mass (more than the percent loss of velocity). When considering momentum (with the previously stated 1.79J example), the speed reduction still has less effect than the mass increase (.20g @ 400fps is about 24gm/s, .25g @ 370fps is about 28gm/s).
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