What's different about Weatherby's new rifle, cartridge?

6.5 WBY RPM tops 3k fps in sub-5-pound gun

Nov 25, 2019 #hunting#biggame

Originally published in the Fall 2019 issue of The Guidefitter Journal
What's different about Weatherby's new rifle, cartridge?

Guides and outfitters who tote a rifle all day, everyday, will appreciate the accuracy and energy of this light new rifle and new cartridge from Weatherby. The new Mark V Backcountry Ti is a sub 5-pound mountain bolt rifle with a suggested retail price of $3,349. It’s made for hunters and guides who go deep into the backcountry or high into the mountains for sheep, goats or deer, and who want to shoot a magnum 6.5mm cartridge but still carry an extremely light rifle that is built form the floorplate up to mitigate recoil.

It has a number of new features, so let’s start from pieces that are unique to Weatherby. The Ti in the name stands for titanium, an element as strong as steel but lighter. The receiver is made from titanium, and you know it’ll be strong. Weatherby got its start in 1945 and is known to this day for creating the strongest receivers in the industry. It’s how Roy Weatherby was able to create hyper-velocity magnum cartridges: he built the first Mark V receiver to handle the higher pressures. With a manufacturer’s suggested retail price of $3,349, the Backcountry Ti will compete with Kimber’s Mountain Ascent and Christiansen’s Summit TI among a few other factory mountain rifles. The Ascent weighs 5 pounds, 12 ounces in a magnum short-action configuration like the .270 WSM, and costs about $2,000 msrp. The Summit is sub 6 pounds at $5,500 retail. The Mark V Ultra Lightweight had been Weatherby’s offering in this mountain rifle category. It weighs roughly 6-7 pounds, depending on the caliber.

At the end of the stock, a new patent pending recoil pad is actually 3D-printed, a first among larger bolt-gun companies as far as we could tell. Weatherby was still working out the exact percentage of reduction in felt recoil when this was going to press. The pad, called the 3D Hex, has a hexagonal pattern specifically made to reduce muzzle lift.

Mark V Backcountry

The new Mark V Backcountry Ti weighs less than 5 pounds, thanks, in part, to its titanium receiver.

Speaking of the muzzle. You’ll have a very light rifle shooting basically a magnum cartridge, so you’ll want to use a muzzle break that pulls away some of that push-back and mitigates muzzle lift. Weatherby will top each Backcountry Ti and Backcountry rifle with a new brake — the Accubrake ST — that they say reduces recoil by 53 percent as compared to using the rifle without it. Both rifles come in 22-, 24- and 26-inch barrels. Sliding down back toward the receiver, Weatherby is equipping each rifle with a TriggerTech trigger. These mechanisms use a free-floating roller between the trigger bar and the sear, so the release is less of a gritty slip and more of a clean rolling break with very little over-travel. Several of the best custom rifle shops are using these types of triggers now. They can help a shooter improve accuracy and get that glass-rod break we all want. The trigger will be factory set to 2.5 pounds. You can adjust it to what suits you best between 2 and 5 pounds. The fluted bolt will have a 6-lug design, traditional to the Mark V .240 actions, and will have a nice 54-degree bolt throw. It will be chambered in a new cartridge — 6.5 WBY RPM.


Weatherby started as a cartridge company so they recently put their minds together to develop a new 6.5mm cartridge for the Mark V, 6-lug action, also know as their standard action. This has always been an underutilized strong and light action but it is long and skinny and could not handle a magnum bolt face. This new cartridge is called the 6.5 WBY RPM. The WBY is for Weatherby, and the RPM stands for Rebated Precision Magnum which was purpose-made for the standard action. This hot-rod will be welcomed by anyone who wants the fastest velocities in a 6.5mm hunting bullet.

The “rebated” part of the name indicates that the back of the case is slightly smaller than the case body thus allowing a smaller bolt face instead of that large magnum bolt face. The “M” is magnum, and this is a fairly large cartridge. Standing next to a 6.5 Creedmoor, the PRM looks like a giant. The RPM will not be as fast as its big brother, the Weatherby 6.5-300, which can push a 127-grain bullet at more than 3,500 fps, but it’s still super-fast. The RPM will send a Barnes 127-grain LRX at 3,225 fps, according to Weatherby tests. (This ammo is expected to cost about $60 or less on the shelf for a box of 20.) A PRC cartridge will send the same bullet at about 3,200 fps.


The latest 6.5mm offering in the industry is the 6.5 WBY RPM, or rebated precision magnum. Here, it’s compared in size and speed to other 6.5mm cartridges using a 127-grain bullet.

Other initial offerings include Hornady’s 140 Interlock, with 3,000 fps muzzle velocity and a $50 msrp, and Nosler’s 140 Accubond, at 3,075 fps, and a $65 msrp. Another major departure from previous Weatherby products is a non-venturi case shoulder, and the bullet is non-belted. Until now, all Weatherby cartridges had a rounded shoulder as opposed to a straight shoulder as found in just about every other cartridge except Ackley Improved chamberings. Over the years, there’s been debate about the function of the rounded shoulder, and whether it’s more style than substance.

Regarding the belt, there’s also debate about whether that’s functional contain Roy Weatherby’s aggressive pressures in his magnums, or it just came from a time when magnum straight cartridges needed something to hold them in battery so they wouldn’t slip into the barrel.
Either way, they’re gone from this cartridge, ad it’s unclear whether all future Weatherby cartridges will follow suit.

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