You may well be right, Miller. But, if the pressure pushing forward gives the gun the forward push, as you say, and not the payload, then could not that ever so brief forward push from the pressure lend to some minute forward movement? I'm not proposing a big forward motion, only a tiny amount in a microsecond. The difference in the recoil is not much, either, as I perceive it, just enough to notice a difference.

May God bless America and those who defend her.