Home Forums Hunting & Shooting Ask The Gunwriters does a semi auto action decrease bullet speed?

I say no - or practically nill but I have a very stubborn technically minded friend who wants a good explanation for if\why a bullet shot out of a semi auto wouldn't be going slower than one out of a bolt? His belief, that I have failed to counter to satisfaction, is that the energy used to cycle the action must be reducing the "accelleration energy" available to the bullet itself? Someone help me with this one please. Feel free to be as mathematical as you like. I was finally able to convince him that muzzle breaks work but that took some doing. Just this weekend I gave him examples on recoil that he was OK with but never got this particular item put to rest.