This is due in part to Roy Weatherby who presented the rifles to royalty, politicians, gun writers and actors including Prince Abdorreza Pahlavi of Iran, Generals James Doolittle (USAF) and Chuck Yeager (USAF), Jack O'Connor, Warren Page, Elgin Gates and Lorne Greene and was able to use this fact as a marketing tool.

Beginning in 1949 Weatherby began building his rifles around the FN Belgian Mauser action.

[3] Roy Weatherby had been disappointed by the length of time that was taken discussing and negotiating before coming to an agreement with his European manufacturing partners.

With five European companies supplying actions, the frequent trips made to Europe left him little time to run the day-to-day business operations in South Gate, California.

[4] Roy Weatherby had found the Mauser-type wanting due to the case head not being completely enclosed and supported within the breech.

While these action types could easily withstand a high pressure of about 70,000 C.U.P., he felt that one which would have the capability of handling 200,000 C.U.P.

He had been aware that many handloaders were overloading their cartridges seeking higher performance, which was resulting in blown primers and ruptured case heads.

This in turn would lead to hot gases making their way through the bolt and into the shooter's face and eyes and causing injuries to his customers.

If a rupture should occur, the bolt would have holes through which hot gases could be vented safely towards the side and away from the shooter's face.

[3] Walter Howe, the editor of the American Rifleman magazine suggested the Mathewson Tool Company of New Haven which had worked with Winchester, Remington, and the U.S. government designing and building prototypes.

It was more streamlined and had a more simplified trigger and safety which would lead to lower manufacturing and tooling costs.

Steyr-Daimler-Puch, which had been manufacturing the Mannlicher rifle, was eager to work with Weatherby, but the high cost of the initial tooling charges of $200,000 was found to have been too excessive.

When Sako of Finland, which was working on the FN Mauser action for Weatherby rifles was approached, it indicated that it had a backlog of production yet to complete and that such a project would have to wait for a year and a half.

[3] While several companies bid on the contract, Weatherby settled on Precision Foundry Inc. (PFI) of San Leandro, California in 1957.

All the parts thus manufactured would be delivered to Weatherby's South Gate facility where the final polishing, bluing, and assembly would take place.

The barrel and stocks were made in-house by Weatherby at the company's South Gate facility.

[4] In 1957 Weatherby went back to Europe to visit J.P. Sauer & Sohn, which was at the time primarily a shotgun manufacturer.

This load did not show any pressure or extraction issues with the new Mark V action but caused a slight sticking of the cartridge case in the Mauser style rifle design.

Firing this load in the Mauser rifle led to a blown primer and extreme difficulty was experienced in extracting the spent case.

[4] Using 86 gr (5.6 g) of Du Pont #4350 the cartridge began to show signs of pressure in the Mark V action.

The primer had been pierced and the exiting gas entered into the bolt and hit the firing pin sleeve, which was loosened slightly.

Shortly after production began in Germany, the bolt body was fluted to provide further positive feeding and extraction of the cartridges.

The original 9 Lug design lacked the bolt fluting and featured a safety mounted on the receiver.

In 1963 Weatherby introduced a scaled down version of the 9 Lug design which was made specifically for chambering smaller varmint cartridges.

The 9 Lug design was found to be too large and too long for use with varmint cartridges and this new action addressed this issue.

Like the Varmintmaster (which predates the 6 Lug/Standard action design) it features six locking lugs arranged in two rows.

This action type is also used by the Weatherby CFP (Center-fire Pistol) as it provided a greater flexibility as to which cartridges could be chambered.