Golly, Johnwill, I think it is a 1911, but I could be wrong, being so ignorant.
Kuhnhausen is very good at working on 1911 type pistols and his books are invaluable to anyone, myself included.
But the other JK shows a pistol with the bullet leaving the barrel (Fig. 30 in my Vol. 2) and says that bullet exit drops the pressure to zero. This is not true, there is still some residual pressure, but let that go for a moment. At that point, he shows the barrel and slide fully locked and in battery.
In fact, the barrel and slide, locked together, begin to move at the same instant the bullet does. The forward motion of the bullet (not gas pressure) produces the equal and opposite reaction of moving the barrel-slide unit backward. The barrel-slide unit is more massive and does not move as fast as the bullet but it does begin to move at that time. Backward pressure on the cartridge case is not a factor, because it is pushing against the slide, which is immovable relative to the barrel at this point.
The barrel-slide unit picks up momentum as the bullet moves down the barrel and when the bullet exits has already begun to unlock.
The momentum carries the barrel and slide back until the barrel drops and unlocks fully from the slide, at which time the slide retains enough momentum to complete compression of the recoil spring, cock the hammer, and prepare to feed another round.
The slide is not propelled forward only by the energy stored in the recoil spring, but also by some of its backward momentum stored when it impacts and bounces off the recoil spring guide. This results in the slide moving forward after firing much faster than it would move under spring energy alone, which gets us back to the question of the rapidity with which the hammer drops on the sear.
Note that it is not (contrary to Fig. 29) the gas pressure itself that causes the pistol to function, it is the motion of the bullet.
In a recoil operated pistol (unlike a blowback) nothing will happen unless the bullet moves. This can be proven (and has been) by plugging up the barrel, leaving just enough room for the cartridge, and then firing the gun. The bullet can't move and the gun will not open. The gas pressure will leak out over time, but the gun will stay locked.
That is the difference between a recoil operated pistol (whether Browning type or another design) and a blowback pistol, where the operation is done solely by gas pressure. Blocking the barrel on a blowback pistol is not recommended.
As to my "fame" or lack of it, my inherent modesty precludes comment.
HTH
Jim