Recoil per se doesn't exist within the gun since the barrels and stock are locked to the action. However, there is a force transmission to any object interfering with the free recoil of the gun. The weak point in the force transmission from the action to the butt is at the stock head and wrist. If the recoil force is too high, you can literally split the wood. And, if the stock develops any looseness, you will get battering of the wood. We would be more correct to say the stock is damaged by transmitting recoil force.
Wear to the hinge pin/hook during firing can occur from battering or relative movement. Battering occurs where there is a bit of off-face so the hook gets a run at the hinge pin. Any strain movement between the hook and pin will result in surface grinding. The action will bend slightly during firing and this changes the position of the hook relative to the pin; maybe only a fraction of a degree, but enough that there is movement. Clean, high pressure lube will minimize metal to metal contact and fine particle grinding, but can't completely eliminate it. Tight on-face, along with hard surfaces on the pin and hook minimize battering.
Let me know if that is not clear.
Not perfectly clear, especially when I try to reconcile this post with the earlier statement...
"Larry, I edited to set my comments apart in red. Also, yes, I went further into wear to locking parts and attributed this to pressure rather than recoil."
Which seems to exclude recoil as a source of wear to locking parts.
The action and barrels lock shut to contain the pressure of firing. They experience the same conditiions with or without something absorbing the recoil force. If the gun were fired in a gravity free vacuum, the gun and ejecta would go opposite directions at velocities that conserve momentum until each encountered some other force. The barrels and action would not know if they were fired on typical earth conditions or in the foregoing vacuum.You say "recoil force doesn't exist within the gun..." and later in the same paragraph refer to "battering of the wood" and the crux of the paragraph seems to say that "transmitted recoil force batters the wood."
Recoil force exists within the gun only when the gun encounters something, typically the shooter's shoulder, that retards rearward motion and, thus, absorbs the rearward force. Joint looseness allows differing velocities between adjacent parts and allows for one to impact the other; battering.Your second paragraph covers "movement, grinding, and battering" (metal wear) without using the word "recoil."
Intentionally as these issues have to do with relative motion between adjacent parts that are joined.Is or,is not, this movement, grinding and battering of metal parts "within the gun" due to the same "transmitted recoil force"
that batters the stock?
No, the stock battering depends on motion of whole gun. If the gun were allowed to recoil freely, there would be not recoil issues with the stock (other than the weight of the stock and that would be a very minimul issue). The action would experience the same issues fired freely or with recoil travel retarded.Is it not true that it is recoil force transmitted to poorly mated metal surfaces that causes their grinding, battering, loosening, i.e.; wear?
No, it is pressure forces.If not, then it's CHAMBER PRESSURE and NOT RECOIL that causes the pin and hook to be battered?
Yes, it is. Clear as mud.
Any better? If you need additional explaination, let me know. 
