Could be fit, or might just be the microphone's greater susceptibility to wind noise.
As for fit- I posted recently about how minor "leaks" at the elastic cuff area of the BAS can result in major wind problems that these windscreens would otherwise be completely capable of handling, and did fully handle once I took measures to correct the problem, working it out in a windy parking lot monitoring through headphones.
On the other front- CM3 is over toward the subcardioid side of cardioid, which places it closer to the omni end of the pattern spectrum and less susceptible to wind and handling noise. If the microphones that jcable77 was using were closer to the fig-8 side of things than the omni side, perhaps supercard/hypercarioids, they would naturally be more susceptible to wind even if the windscreen fit was correct.