Strength is a pro.
The below excerpt is from pg. 198 of "Weatherby: The Man. The Gun. The Legend." Weatherby was testing his new Mark V action chambered in .300 Wby Magnum.
"The first test firing was with a cartridge that had been loaded with 82 grains of 4350 DuPont powder, using the 180-gr bullet. This load gave and average breech pressure of 65,000 psi. After firing, there was no sign of pressure and extraction was easy. The same 82-gr. load was fired in the Mauser action and a slight sticking of the cartridge case resulted. Four more loads with the powder charge being increased in two-grain increments were prepared, each one using 4350 powder and the 180-gr. bullet. After firing the 84-gr. load, there was still no sign of pressure and no sticking of the cartridge case, even though the breech pressure had been increased to almost 75,000 psi. When firing this 84-gr. load in the Mauser action, it caused a blown primer and it was almost an impossibility to extract the cartridge case....For the final test the cartridge case was filled with powder, leveling it off at the top. This was 90-gr. of powder. After firing, the bolt was difficult to open, but without exerting too much pressure it could be opened and the case extracted...The severest test was when a 220-gr. bullet was placed in the bore, and a standard 180-gr. round fired in back of it. On this particular firing, the head diameter of the cartridge increased to .545 inches. It was also noted after these additional 15 firings that the head space was set back a mere .001."
Jared