...during the firing cycle, there must have been a significant fraction of the total volume of the air charge between the piston crown and the port before the valve opened.
So, whether the piston moves or not, the effect would be the same. If the port is so restrictive as to interfere with that fraction of the charge doing its share to pressurize the bore and push the pellet, velocity will suffer. No?
This forum is not affiliated with the Crosman Corporation in any way// Information presented in this forum is intended for informational purposes only; use at your own risk//Posts made to this forum are solely the opinion of the individual member