The K button should be on a separate circuit. The recoil on the gun is instigated by the negative feed that the up stick produces. I modify the tranmitter to move the k button to the left stick. That way upward stick movement gets everything happening at once. So in effect what happens in my recoils is exacly what is happening in yours. I have had double recoils or recoils that won't stop, but it has always been caused by the contact swtich.

Just for fun have someone lightly grip the bbl to slow down the return and see if that fixes the occurance. If it does, then I suggest a resistor in the main power supply to the gun to slow it down.

Dan