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The very first link repeats the myth that 7.62x51 is 50,000PSI It's 50,000 CUP not PSI Quit mixing up units please. Tried of seeing that misinformation repeated over and over again..
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Average operation pressure of 7.62 NATO M80 Ball is 48,000 CUP or 50,000 PSI EPVAT ( the international standard).
The operating pressure of M118 Special Ball and M118 LR are 52,000 CUP, no EPVAT equivalent given.
HPT (military Proof loads) are 64,000 CUP.
Theres no direct correlation between CUP and PSI readings and the difference varies from one cartridge type to another because of differing case capacities and configurations. A few cartridges such as the .30 carbine have CUP and PSI figures that are identical.
PS
Most Milspec propellents contain flash suppressant and coolant additives , usually Calcium based, that add an abrasive element to fouling and increase bore wear.
As for laquer sealents at the case mouth and asphaltum sealants inside the case neck, I've cleaned enough military rifles to know that these do leave deposits in a bore.
Laquer coated steel cases are a problem on their own, and the waxy protective coating found on some older brass MG cartridges may have a deletrious effect when used in a rifle. Only heard of wax coating used on some South African .303 MG ammo placed in long term storage.