Gregg, the comparisons I used with the 7.9 gr. and the 14.3 gr. pellets will give almost equal energy levels in the Beeman R-9 .177 and .22. These particular pellets have a higher ballistic coefficient so if you use a different pellet for this energy comparison test you will get a different result.Bottom line is in the CFX power class with high ballistic coefficient pellets you will be hard pressed to have measurable advantages in"killing effectiveness" I suggested the .177 because of it's flatter trajectory which for most people means it's easier to hit the target. If you just shoot the lightest, fastest .177 pellets they will have considerably less energy at 50yards than the slower, heavier .22 pellet. So you see it's not all about velocity. Pellet choice matters too. Hope this clears that up. Good luck and happy shooting.