The Weatherby Mark V Accumark is a bolt-action rifle chambered in .338-378 Weatherby Magnum. The 28-inch #3-contour barrel is fluted and threaded for the Accubrake ST muzzle brake. The stock is hand-laid fiberglass with a matte gel coat finish and a Monte Carlo cheekpiece. Overall length is 48.25 inches, weight is 8.3 lbs, capacity is 2+1 rounds, and the exterior finish is Graphite Black Cerakote. 
 

Key Specifications 

• Model: Mark V Accumark 
• Caliber: .338-378 Weatherby Magnum 
• Barrel Length: 28 inches (#3 contour) 
• Capacity: 2+1 rounds 
• Weight: 8.3 lbs 
• Overall Length: 48.25 inches 
• Twist Rate: 1:10 inches 
• Finish Color: Graphite Black Cerakote 
   

Features 

• Accubrake ST Muzzle Brake: Reduces felt recoil, which matters significantly with the .338-378 Wby Mag. 
• TriggerTech Adjustable Trigger: Crisp pull with minimal creep, user-adjustable for preferred weight. 
• Hand-laid Monte Carlo Stock: Fiberglass construction with matte gel coat helps stabilize the action and resists weather. 
• Sub-MOA Guarantee: Weatherby guarantees minute-of-angle accuracy at 100 yards. 
   

Usage 

The .338-378 Weatherby Magnum is a flat-shooting, high-velocity cartridge suited to large and dangerous game at long range. The Mark V Accumark is built around that use case — the long barrel maximizes velocity, the muzzle brake tames the recoil to something manageable, and the Sub-MOA guarantee reflects real quality control in the barreled action. It also serves long-range competitive shooters who want a known-accurate platform.

Owners of the Mark V Accumark tend to be enthusiastic about its accuracy. Tight groups at extended distances come up consistently in user reports, and the Sub-MOA guarantee appears to reflect actual performance rather than just marketing language based on what owners share.

Build quality gets strong marks across the board. The fiberglass stock, Cerakote finish, and TriggerTech trigger are frequently singled out as highlights. The Accubrake ST gets credit for making the .338-378 Wby Mag more comfortable to shoot than the caliber's paper specs might suggest.

Weight is a recurring conversation point. At 8.3 lbs the rifle is on the heavier side for a hunting rifle, and some users note it becomes fatiguing on long carries. Most acknowledge that the weight helps with recoil management at the bench.

Pricing generates some debate. Weatherby commands a premium, and not all buyers feel the cost gap versus competitors is fully justified. Customer service experiences are generally positive, though occasional delays come up in longer threads.

Customization and aftermarket accessory discussions are common among owners, indicating an active community around this platform.