"Nothing shoots flatter, hits harder or is more accurate. Guaranteed.”
There are few rifle enthusiasts and big-game hunters worldwide who wouldn’t recognize the Weatherby slogan. Its purpose, however, is more than to simply serve as a catchword; it’s a promise that drives the company’s decision-making process. A recommitment to those stated qualities served as the catalyst behind Weatherby’s recent decision to bring home, to Paso Robles, Calif., production of the company’s flagship rifle, the Mark V.
Examining The Mark V
From 1945 until 1958, the latter being the Mark V’s introductory year, Weatherby utilized existing actions from Fabrique Nationale, Schultz & Larsen, Mathieu and Brevex, among others, as well as customer-supplied rifles re-chambered to accept his proprietary cartridges. Such practices continued until 1961.
Weatherby revealed the first iteration of his action in early 1955, while in Washington, D.C., attending NRA’s Annual Meetings. Encouraged by prominent firearm industry figures of the day, he continued to refine his action until the fifth—and final—variant was transformed into a working rifle. Playing on Mercury Outboard Motor’s use of “Mark” followed by the model designation—suggested by motor boat champion, world renowned hunter, and Weatherby Award winner Elgin Gates—Roy Weatherby coined the fifth prototype of his action/rifle the “Mark V.”
When designing the Mark V action, strength was paramount to Weatherby; in fact, he wanted an action capable of withstanding an unheard of 200,000-copper units of pressure (c.u.p.), whereas most others of the time succumbed around 70,000 c.u.p. He also demanded a means to prevent propellant gasses from reaching the shooter’s face in instances of pierced primers or case-head separation. Subsequent “torture” testing proved the action to be incredibly resilient, and from that came the phrases “The world’s strongest action” and “strongest bolt action ever designed.”
What, exactly, was done to enhance safety? First, the recessed bolt face encloses the cartridge’s case head, and the breech end of the barrel is likewise recessed to accept the forward portion of bolt. Both are surrounded by the receiver ring, providing a total of three layers of steel for added protection.
Weatherby didn’t stop there, however. Several measures were also taken to prevent gas flowback. “Gases flowing around the extractor are deflected by a shoulder located behind the locking lugs,” explains company literature. That’s fine for case-head separation, but what happens to propellant gases vented through a pierced primer? Weatherby included three holes in the bolt body that vent gases out of the loading port. Should gas bypass the openings, the shrouded bolt sleeve directs it downward, away from the shooter.
Lastly, the Mark V’s one-piece forged bolt has three sets of three lugs for nine total (except for non-magnum chamberings, which have three sets of two for six altogether), which, unlike traditional lug designs, do not extend beyond the body’s diameter. Although smaller in size than the lugs of a two-lug (or dual-opposed) bolt, the combined engagement area of the Mark V’s bolt is greater, resulting in additional strength. The lug configuration also enables a shorter, 54-degree bolt lift, as opposed to 90 degrees on a two-lug design, or even 60 degrees for bolts with three large lugs. In addition to faster bolt cycling, it provides greater bolt-to-scope clearance.
The Mark V’s full-diameter bolt has longitudinal flutes spanning nearly the body’s entire length, and their purpose is to reduce surface area and capture debris, both of which facilitate smooth cycling. They’re visually appealing, too. Extraction is provided by a spring-powered unit, and the ejector is of the plunger type. On the right rear portion of the bolt, beside the shroud is the safety, for which Weatherby coined the name “Direct Striker Intervention.” In the rear position, the bolt and firing pin are locked and the sear is disengaged, while the forward position readies the rifle to fire. A series of ribs on the tab enhance purchase, and it is easily manipulated with the thumb. The bolt also has a cocking indicator that projects from the rear, into the tang area.
Although the Mark V’s receiver and all its parts were originally investment cast, all are now, and have long been, machined from forged 4140 chromoly steel. The receiver has an oversize integral recoil lug, and there is no raceway or guide rail in the traditional sense; however, thanks to the full-diameter bolt, there’s minimal side-to-side movement during cycling. Since the barrel is devoid of sights, the receiver is drilled and tapped to accept scope bases. Weights for standard and magnum actions are 25.9 ounces and 35.9 ounces, respectively.
Whereas most Mark V rifles feature hammer-forged, button-rifled Criterion barrels, others, such as the Tactical Response Rifle (TRR) and TRR RC, have Krieger barrels. Depending on the model, the barrel—4140 steel for blued versions, 410 stainless steel on Accumark, Ultra Lightweight and Threat Response Custom Magnum—may (or may not) have longitudinal flutes to both lower weight and enhance heat dissipation via additional exposed surface area. Muzzle crowns are either of the recessed target style or radiused “field” type. Also, some chamberings, such as .30-.378 Wby. Mag., .338-.378 Wby. Mag., .378 Wby. Mag., .416 Wby. Mag. and .460 Wby. Mag., as well as all options in the Mark V Accumark, have Weatherby’s recoil-reducing Accubrake installed. Reportedly, recoil reduction is upward of 53 percent. Thread protectors are provided for when the devices are not used. Brakes can be fitted to any rifle, however, as an option.
The Mark V has an all-steel trigger assembly of the company’s own design. From the factory, sear engagement is set at 0.008 inches to 0.014 inches and trigger pull weight is 3 pounds, 8 ounces, though both settings can be adjusted. There is virtually no discernible creep or overtravel.
Perhaps the most distinguishable feature of a Mark V rifle, from the Accumark and Deluxe to the Synthetic and Light is its raised-comb Monte Carlo-style stock with cast off dimensions. Deluxe, Lasermark, Sporter, Ultramark and Euromark Mark Vs have stocks in standard, select, “AA” fancy-grade or “AAA” exhibition-grade walnut, while the Synthetic has an injection-molded version and the Fibermark Composite, Ultra Lightweight and Accumark have hand-laminated iterations made from a combination of aramid, graphite unidirectional fibers and fiberglass. The latter two have a CNC-machined, 6061-T6 aluminum bedding “plate” molded into the stock that provides a rigid platform for securing the action to the stock, enhancing consistency and accuracy. As for the dual-tapered fore-end, it has a flat bottom for better stability. Capping the buttstock is a pliable Pachmayr Decelerator recoil pad. Finishing out the rifle is a one-piece bottom metal unit with integral trigger guard and drop-out floorplate.