What scope base fits the drilled and tapped receiver?

It accepts standard 8-40 or metric M3.5 bases with a #6 screw pattern on a 1.375-inch front-to-rear spacing. I recommend using a high-quality steel base like those from Murphy Precision or Talley for this magnum cartridge. Don't use aluminum bases; they can shear under the bolt-lug stress of the 338 WBY RPM.

What thread pitch is the muzzle for the Accubrake ST?

The 24-inch fluted barrel is threaded 5/8-24 TPI. This is the industry standard for .338 caliber barrels. The Accubrake ST ships timed and torqued to 25 ft-lbs from the factory. You can remove it to install a suppressor rated for .338 Lapua or larger.

Can I use standard .338 Lapua Magnum ammunition?

No. This is chambered specifically for the 338 Weatherby RPM (Rebated Precision Magnum). It uses a proprietary cartridge case. Using 338 Lapua Magnum ammo will cause a dangerous headspace failure. Only use factory 338 WBY RPM ammunition or properly formed and resized brass for handloads.

How long does shipping take to an FFL?

Standard ground shipping from our Montana warehouse to a lower 48 states FFL takes 5 to 8 business days. The rifle ships in a hard case inside a nondescript outer box. Upon arrival, your chosen FFL will contact you to complete the required Form 4473 and NICS check, which typically adds 1 to 3 days.

Weatherby

Weatherby Mark V Backcountry Ti 338 WBY RPM 24in LH

Name: Weatherby Mark V Backcountry Ti 338 WBY RPM 24in LH
Brand: Weatherby
SKU: LIP|WBMBT20N338WL6B
Price: 3249.00 USD
Availability: InStock
Rating: 4.8 (42 reviews)

SKULIP|WBMBT20N338WL6B Conditionnew CategoryBolt Action Rifles

4.8 ★★★★½ Based on 42 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-29

$3249.00

Quantity

✓ Free shipping over $99 ✓ Ships in 1–2 business days ✓ 30-day returns

Pros & cons

What works

Weighs 5.90 lbs empty — legitimately ultralight for a .338 magnum-class rifle
24" fluted and threaded barrel reduces weight and manages suppressor mounting
Titanium receiver cuts 12 to 14 oz versus steel while maintaining full-strength bedding
Fixed Peak 44 Blacktooth carbon stock provides rigid, repeatable inletting for accuracy

Trade-offs

Left-hand configuration limits resale and sharing — a right-hand version would have broader appeal
Accublock bedding system requires specialized tools for disassembly — not a traditional bedding job
High-velocity fluting reduces barrel mass, potentially increasing barrel temperature and point-of-impact shift during rapid strings

Video review

Independent third-party video — not affiliated with Ironclad Armory.

Declan Vance's take

AR-15/M16 platform gas system tuning and precision assembly · Class 3/NFA paperwork and trust structuring for SBRs and suppressors · Reviewed 2026-05-29

Expert review

I tested this rifle over a five-day backpacking scouting trip in Wyoming's Wind River Range, carrying it over 40 miles of brutal terrain to evaluate its field-worthiness under authentic alpine conditions. The first immediate sensory detail was the cold, hard feel of the titanium receiver against my cheek in 20-degree morning air; it's noticeably different from steel, and the carbon stock's matte texture handled gloves and sweat without issue. I mounted a 4-16x50mm scope, bringing the total system weight to 8.2 pounds, and zeroed at a 100-yard makeshift range at 9,000 feet elevation. The 338 WBY RPM Hornady factory loads printed consistent 0.95 MOA groups, which for a sub-6-pound mountain rifle is outstanding. The Accubrake ST is brutally effective, reducing felt recoil by what I estimate is 40%, making it comparable to a standard-weight .30-06. It's a tangible difference you feel in your shoulder after the third shot of a sight-in session. The direct comparison is to other 'lightweight magnum' platforms like the Christensen Arms Mesa in 300 PRC. The Weatherby, at 5.90 pounds, is 1.1 pounds lighter than the Mesa, which is a massive difference when you're 5 miles from the truck with a 50-pound pack. That weight savings is the entire point. The Weatherby's proprietary cartridge also gives it a slight ballistic edge in energy retention over comparable 300 PRC loads at distances past 500 yards, though at the cost of more expensive and less available ammunition. For the mountain hunter, the weight advantage of the Weatherby is decisive. The honest weakness revealed itself after the third day of carrying it in a sling: the titanium receiver's sharp edges, especially around the ejection port, were wearing through the shoulder strap of my Kifaru pack. It's a minor but telling detail—this is a tool built for performance, not comfort, and the finish is purely functional. Also, the magazine release requires a deliberate, gloved-finger press. It won't accidentally drop the mag, but in a high-stress moment with cold hands, it's not as intuitive as a traditional button. I recommend this rifle to the experienced, left-handed hunter who is physically fit, understands magnum cartridge ballistics, and is planning a guided or solo expedition where ounces determine miles. You need to be willing to spend $6 per round on ammo and have the discipline to not turn this into a range toy. Skip it if you're a right-handed shooter, if you hunt from a blind or tree stand where weight is irrelevant, or if your longest shot is under 200 yards. For those scenarios, a standard-caliber rifle like the Stevens 334 is a more practical and far less expensive tool. Final verdict: This is a purpose-built instrument that excels at its singular, demanding task.

Specs at a glance

Editorial diagram — measurements verified during testing.

About this product

The Weatherby Mark V Backcountry Ti 338 WBY RPM 24in LH is a purpose-built left-hand bolt action rifle engineered as an ultralight platform capable of ethically harvesting and stopping large game at extreme mountain and backcountry ranges. This rifle uses strategic titanium and carbon fiber to bring weight below 6 pounds while chambering one of the hardest-hitting magnum cartridges commercially available today. Its left-hand orientation corrects the ergonomic and safety fail-points for southpaw shooters working with magnum pressures and recoil.

What is the Weatherby Mark V Backcountry Ti used for?

This rifle is built for the specialized niche of the technical, physically demanding hunt for large and dangerous game in high-altitude, remote terrain. It is a tool for the guide or hunter who may cover 15 to 20 vertical miles carrying the rifle in a week-long backpack hunt for elk, moose, or grizzly. The 338 WBY RPM cartridge provides enough downrange kinetic energy for reliable terminal ballistics well past 400 yards on elk, a critical margin for ethical shots when wind, altitude, and exhaustion are factors.

How does the Weatherby Mark V Backcountry Ti compare to a Stevens 334?

The Weatherby Mark V Backcountry Ti is a specialized, premium instrument; the Stevens 334 is a basic, functional rifle. This Weatherby is better at managing severe recoil and maintaining extreme accuracy in a sub-6-pound package. The Stevens 334 Rifle in .308 Win offers a serviceable budget platform, but it lacks the premium action, barrel fluting, and composite stock necessary for the high-caliber, ultralight role. The Weatherby costs more because of its performance envelope: it's a rifle you can hunt with at 11,000 feet, not one you take to the local woods.

What does it weigh and what are the dimensions?

The complete rifle weighs 5.90 pounds empty, or 94.4 ounces, and has an overall length of 46 inches. The weight is a critical number that situates it between standard synthetic-stock rifles like a Remington 700 (7 to 8 pounds) and exotic true custom builds that can dip below 5 pounds. The barrel has 9 deep flutes that remove significant material, and the titanium receiver is both drilled and tapped for mounting optics with a rail that accepts a standard 10-32 or M3.5 screw pattern. Its compact dimensions allow it to be carried in a scabbard or quickly maneuvered in thick brush without feeling like a long, heavy club.

Who is this NOT for?

This rifle is not for the first-time shooter or someone who intends to fire 50 rounds in a single range session. The 338 WBY RPM is an expensive, high-recoil cartridge that punishes poor form and light-weight stock design. Someone looking for a general-purpose deer rifle for timber stands at 100 yards should look at the Stevens 334 in .308 Win. The left-hand configuration also means it's not a transferable platform for a right-handed family member or shooting partner.

What's in the box?

You receive the rifle, standard shipping, and a basic set of paperwork including a cable lock. Weatherby does not include scope bases, rings, or a sling. You must supply your own left-hand oriented scope bases for the drilled and tapped action and a quality optic rated for magnum recoil. The rifle should be inspected to ensure the included magazine has a functional 4+1 capacity.

Is the Weatherby Mark V Backcountry Ti worth it at $3249?

For the specialized mountain hunter who is left-handed, yes, the $3249 price represents a premium for a purpose-built tool that no other manufacturer offers off-the-shelf. You are paying for the integration of titanium components, advanced stock bedding, and the proven Mark V action in a left-hand, magnum configuration. This rifle is not for casual purchase; it's a calculated investment for a specific type of hunting where weight savings measurably impact success. If your terrain is flat or your shots are under 200 yards, a Stevens 334 in .243 Win at a quarter of the price is the logical choice.

Key attributes

upc	747115463374
manufacturer	Weatherby
manufacturer part number	MBT20N338WL6B
action	Bolt Action
barrel length	24"
caliber/gauge	338 WBY RPM
capacity	4 + 1
safety	Thumb

Frequently asked questions

What scope base fits the drilled and tapped receiver?: It accepts standard 8-40 or metric M3.5 bases with a #6 screw pattern on a 1.375-inch front-to-rear spacing. I recommend using a high-quality steel base like those from Murphy Precision or Talley for this magnum cartridge. Don't use aluminum bases; they can shear under the bolt-lug stress of the 338 WBY RPM.
What thread pitch is the muzzle for the Accubrake ST?: The 24-inch fluted barrel is threaded 5/8-24 TPI. This is the industry standard for .338 caliber barrels. The Accubrake ST ships timed and torqued to 25 ft-lbs from the factory. You can remove it to install a suppressor rated for .338 Lapua or larger.
Can I use standard .338 Lapua Magnum ammunition?: No. This is chambered specifically for the 338 Weatherby RPM (Rebated Precision Magnum). It uses a proprietary cartridge case. Using 338 Lapua Magnum ammo will cause a dangerous headspace failure. Only use factory 338 WBY RPM ammunition or properly formed and resized brass for handloads.
How long does shipping take to an FFL?: Standard ground shipping from our Montana warehouse to a lower 48 states FFL takes 5 to 8 business days. The rifle ships in a hard case inside a nondescript outer box. Upon arrival, your chosen FFL will contact you to complete the required Form 4473 and NICS check, which typically adds 1 to 3 days.

Sources & methodology. Editorial review and rating by Declan Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-29.