First Look: 6.5-300 Weatherby Is Smoking Hot

The hottest factory 6.5mm hunting cartridge ever is here! We’ve got an first-hand breakdown of the new 6.5-300 Weatherby.

First Look: 6.5-300 Weatherby Is Smoking Hot

Back in the late 1970s and 1980s, I worked not far from the South Gate, California, home of Weatherby. Weatherby’s founder, Roy, was one of the real innovators of rifle cartridges. Roy believed lighter bullets traveling at high speed would deliver superior hydrostatic shock to an animal, which goes against day’s common belief that hunting cartridges are best when employed by heavy bullets at medium velocity. And when coupled with their flatter trajectory, on-target hits were a much surer thing.

Roy Weatherby’s vision has lasted for decades, and today the company produces a full line of Weatherby Magnum cartridges ranging from the little .224 Wby. Mag. all the up through the humongous .460 Wby. Mag. Their latest offering is the 6.5-300 Wby. Mag.

“We have taken the ‘Nothing Shoots Flatter, Hits Harder Or Is More Accurate’ motto to a whole new level with what is now the fastest production 6.5mm cartridge in the world,” said Adam Weatherby, Executive Vice President and Chief Operating Officer of Weatherby, Inc. “The speed and energy of this cartridge is unprecedented, all while exhibiting very manageable recoil.”

The 6.5mm bullets, with their long-for-weight length and high ballistic coefficient (BC), have long been the rage with long-range match shooters, as well as big game hunters who strive for extreme accuracy at extended distances. The 6.5x300 Weatherby — essentially a .300 Wby. Mag. case — necked down to accept a 6.5mm (0.255 inch) bullets is something wildcatters have played with for many years, but as of this writing I can find no safe published data for handloaders. In fact, Roy himself built a 6.5-300 back in the early 1950s. Weatherby is initially offering three different bullet options in loaded ammunition for the 6.5-300 — a 127-grain Barnes LRX, 130-grain Swift Scirocco and 140-grain Swift A-Frame. The cartridge is being chambered in the new Mark V family of rifles and offered in the Accumark, Accumark RC and Ultra Lightweight models. The first rifles began making it to dealers just after the first of the year.

My test rifle is one of the new Mark V Accumarks, which feature the first significant refinements of this rifle since its original introduction in 1958. The new Mark V stocks have been ergonomically enhanced with a slimmer forearm with sharper, more distinctive lines and contours. The grip diameter has been reduced, a slight right-hand palm swell has been added and overall weight has been reduced. The Mark V now features the LXX Trigger, with engagement surfaces that have been precision ground and polished, and overall tolerances refined. A new, wider trigger face also increases trigger-to-finger contact and is adjustable down to 2 ½ pounds. Also featured are a fluted bolt body, a 54-degree bolt lift that is the shortest in the industry, a one-piece forged and machined receiver that features an integral recoil lug for strength and structural integrity, and a visual cocking indicator. It has a 26-inch #3 contour barrel with 1:8 twist and weighs in at 8.2 pounds bare.

Best of all, the Mark V comes with Weatherby’s sub-MOA accuracy guarantee. So, off to the range I went to see about that.

I had both the 127- and 130-gain factory loads to play with. First task? The chronograph. My chronograph showed the 127-grain bullet clocking a three-shot average of 3,545 fps, and the 130-gain load coming out at right at 3,485 fps — both smoking hot. Being in southern Arizona in August I start shooting at daylight when air temperatures are a manageable 70-something degrees, but before I was done the thermometer read 105. To keep the rifle from overheating every couple of shots I ran a rag soaked with ice water over the barrel; I also clean the barrel after every 10 shots.

This rifle liked both loads, but while the 127-grain LRX bullet gave me consistent three-shot groups at 100 yards measuring about 1 inch, the 130-grain Swift Scirocco was spectacular. Twice out of five groups I got a little 3-hole cloverleaf measuring a ¼ inch; the five-shot group average was a ½ inch. Shooting with the aid of a sled-type Champion Premium Shooting Rest helped, no doubt! To round out the morning I went prone and banged some steel gongs out to 500 yards.

There are already internet detractors out there saying stuff like, “Who cares?” and “It’s over-bored” and “It will go through barrels like poop through a goose!” and so on.

To that I say, good points all. I also say, you don’t choose a Weatherby cartridge because you like slow bullets. You want your rifle to shoot fast and flat. My take? The 6.5 Wby. Mag. cartridge is fast and accurate — at least in this rifle. I would not hesitate to take it on any big-game hunt where long-range shooting might be required, which means pretty much any big-game hunt in North America. I can’t wait for the season to get here so I can do just that!


Charts provided by Weatherby, Inc.

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