Weatherby's Mark V Accumark RC 338-378 WM Part 1

The Weatherby Mark V Accumark represents to an experienced hunter, what Snap-On Tools represent to an experienced mechanic; enhanced capabilities and features for the accomplished and with a price tag to match. I’d guess that the Mark V Accumark and Mark V Deluxe also represent a fork in the road that leads Weatherby into two quite different markets.One path follows a firearm owner to the range where a Mark V Deluxe beauty, with its polished, deep blued steel hardware and fancy high gloss walnut won’t be compromised; a day of precise shooting and firing line admiration or gentlemanly fair weather hunting. The other path is for those who hunt rough and challenging terrain in search of big and dangerous game and do not have the time or opportunity to coddle a firearm.

The Deluxe requires a certain degree of finesse in handling to preserve its show quality appearance. The composite stocked, stainless steel Accumark is a tough, durable and accurate hunting rifle that can deliver within a harsh environment  and come out looking none the worse for wear. That is not to say the Accumark isn’t an example of functional beauty.

Current production…

I would not suggest that the Weatherby Mark V Accumark has ever been anything other than a nicely done firearm, however, I would be remiss if I didn’t note that the Accumark coming out of Weatherby’s Paso Robles, California facility these days is particularly clean. Stainless, alloy and aluminum hardware and hand laid composite/fiberglass stocks are uniform in finish, color and luster as applicable. I am glad to see Weatherby’s flagship product line marked “Made in the USA”.

Key features…

Contributing directly to the Mark V Accumark’s accuracy is the hand laid composite stock made of aramid, graphite unidirectional fibers and fiberglass. At the core of the stock is a rigid CNC machined bedding plate that is made of aircraft-grade 6061 T-6 aluminum. The plate not only locates the Mark V’s receiver, it also extends through the stock’s wrist and well into the rifle’s buttstock for maximum assembly reinforcement and alignment.

Because of its composition and mechanical design, the stock/rifle assembly is virtually unaffected by changes in humidity and temperature. The barrel is floated to assure a heating barrel will not yield odd pressure points along the barrel channel when expanding.

The action is located to the stock at the action’s recoil lug that is keyed and glass bedded to the stock’s bedding plate and at the receiver’s tang. There is no critical wood inletting with the potential of compromising action and barrel bedding. Consistent accuracy is literally guaranteed for any and every Accumark.

The Weatherby Mark V Accumark has a two position safety “On” or “Off” which Weatherby refers to as a Direct Striker Intervention Safety. When in the “On” position the safety locks the firing pin in position. locks the bolt closed and disengages the sear to render the trigger inoperable.

The Mark V trigger is factory tuned and fully adjustable for sear engagement and pull weight. Sear engagement is factory set between 0.008″ to 0.014″. Weatherby recommends that any further adjustment be made at a Weatherby Service Center or qualified gunsmith. Pull weight is set to the factory at a nominal 3.5 lbs, however, that setting is owner adjustable. The subject forearm was set to just about 4 with no creep or noticeable overtravel. I reduced pull to close to 3 lbs for the live fire phase.

The use of aluminum or, as our British brothers say, alumminumininium

With the structural duties of stock and barreled action bonding accomplished between action and stock bedding frame, weight could be saved by using light aluminum for the bottom metal. Black anodized and sporting both the Weatherby logo and the Range Certified designation, the locking pieces for the hinged floorplate, follower and magazine box are all made of steel to endure use.

Lock up like a bank vault

The Weatherby’s tri-radial placement of locking lugs yields a 54º bolt lift, versus the 90º bolt lift of the twin lug Remington bolt on the left. The Weatherby flutes reduce bearing surface, which reduced drag. The three ports are for safe redirecting of gas pressure in the event of cartridge case failure. The Weatherby Mark V utilized a bolt body that is as large in diameter as the big 338-378 Weatherby Magnum’s nine locking lugs. A cartridge case head is enclosed in the bolt head, which is enclosed in the barrel, which is enclosed in the receiver for an incredible amount of support under pressure.

A much maligned, well designed, brake

Perhaps Weatherby has made some revision to its Weatherby Accubrake, or perhaps it is my relic memory of events, but it seems the Accubrake reduced recoil as effectively as always, about 53%, but it seems that noise and pressure levels have been reduced. Didn’t notice a pressure wave and didn’t notice more than the bark of a really big cartridge to the extent that brake on or off seemed about the same.

In regard to recoil, the 338-378 Weatherby recoils with… conviction. However, Weatherby stock geometry is such that recoil energy is kept away from the shooter’s face, there is no rotator cuff hyperextension and the excellent recoil pad protects the shoulder. For folks who are more recoil sensitive, the brake is very effective with a 53% recoil reduction.

Range Certified

While the Mark V Accumark carries a 1 1/2″ 100 yard 3 shot group guarantee, an Accumark with an RC suffix guarantees a 0.99″ or less group size with factory ammunition. Each rifle is range tested before leaving Weatherby and packaged with an Oehler Model 83 generated target and data indicating tested group size, specific ammunition used and environmental conditions at the time of testing. There is even a signoff from Ed Weatherby. The subject rifle’s target indicated a three shot, 100 yard group  size of 0.450″ with Weatherby factory 225 grain Barnes TSX ammo.

Until Part 2…