Hello Todd, The above posters have all given good suggestions. The consensus seems to be that even with your 11fpe gun, at the close distances you are shooting, you should be able to consistently cleanly kill squirrels regardless of the pellet you shoot if you brain shoot or heart/lung/spine shoot. You will waste some of your pellets precious energy if you try to drive the shot through a foreleg before it gets to the ribcage which it must punch through to reach the vitals.fwiw.About that better penetration thing you mentioned. Actually it does make sense that the heavier pellet seems to penetrate better when compared to a lighter pellet when both have equal energy It's a classic case of equal on paper only. The inertia of that heavier pellet helps to drive it deeper.Keep shooting at those squirrels. They are great for learning about shot placement and if you are fan of fried squirrel I salute your good sense.