SAAMI Accepts 6.5-300 Weatherby Magnum Cartridge

Weatherby-6.5-300x3.56 in. 4cFor the first time in decades, Weatherby unleashed a new cartridge in 2016, this one is based on a necked-down .300 Weatherby Magnum: the 6.5-300 Weatherby Magnum. The Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI), the firearms and ammunition industry’s technical standards-setting organization, recently announced the acceptance of the new cartridge and chamber standard.

This cartridge isn’t exactly new, even though Weatherby is billing it that way. Roy Weatherby built a 6.5-300 in the early 1950s, as evidenced by an old Mauser-action rifle in the company’s collection. Also, in the early 1970s, a group of benchrest wildcatters built rifles chambered for the 6.5-300 WWH (Weatherby Wright Hoyer), a 6.5mm cartridge using the .300 Weatherby as the parent case.

In keeping with Weatherby’s DNA, this is a high-velocity centerfire rifle cartridge that, when combined with high Ballistic Coefficient (BC) projectiles, targets the bolt-action rifle, long-range shooting market.

“This 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 and worthy of carrying the Weatherby name, all while exhibiting very manageable recoil.”

SAAMI was founded in 1926 at the request of the federal government and tasked with coordinating the industry’s technical data, creating and publishing industry standards for interchangeability, reliability, performance, quality and product safety and promote safe and responsible use of firearms.

The company released specs on three loads: a 127-grain Barnes LRX running at 3,531 fps, a 130-grain Swift Scirocco shooting at 3,475 fps and a 140-grain Swift A-Frame scooting along at 3,395 fps.  The 6.5-300 Weatherby Magnum was chambered in the New Mark V family of rifles and offered in the Accumark, Accumark RC and Ultra Lightweight models for 2016.

All the rifles have 26-inch barrels (the Ultra Lightweight also has a 2-inch muzzle brake) with 1-in-8-inch twists. Factory-supplied ballistics show that with a 300-yard zero, the 127-grain Barnes drops 7.12 inches at 400 yards and 18.99 inches at 500 yards. The drop figures for the 130-grain Swift are 7.2 inches and 19.0 inches at 400 and 500 yards, respectively. Drops for the 140-grain A-Frame are 8.6 and 23.3 at 400 and 500 yards, respectively.

What do you think of the 6.5-300 Weatherby Magnum’s introduction?

8 thoughts on “SAAMI Accepts 6.5-300 Weatherby Magnum Cartridge”

  1. I just got 3332 fps average from my 6.5-06 Ackley. 62.0 gr of Reloader 26 and 130 Berger Hunting VLDs. 26 inch nitrocarburized barrel. I ran as high as 62.7 gr and the primers were still snug. The 6.5-300 Weatherby doesn’t gain that much in 26 inches of barrel. With Ruger #1 or Browning M78 highwall you could tote 28 inches of barrel comfortably and gain more. I have 6.5 WSM and 6.5-284 also at home and I don’t see the need. The 6.5 WSM will carry a ton of energy to 500 yards. Is it an elk rifle or deer rifle?

  2. Send me a Weatherby Rifle chambered for the 6.5-300 and a few hundred rounds, and I would be glad to give you guys my thoughts! Sounds like a great cartridge! Would love to try it out, problem is not only having to purchase the gun, but all those dies,casings, bullets, powder, etc to get into Handloading these.
    Most all rifle cartridges are so expensive. Some of my caliber (7mm Rem. Mag.) Can cost 50 dollars or more for 20 factory rounds. I can hand load for less than half ( if I have the casings already ) great articles, keep them coming!

  3. I have never hears of this caliber, why can’t SAAMI approve popular wildcat calibers such as 6mmx45

  4. Another great round for weatherby with all new calibers coming out such as the 26 Nosler , 28 Nosler , 30 Nosler , and now the king of all 6.5 calibers . Hunters & bench rest shooters have finally fiquired out you need a long bullet to dope the wind at long ranges and weatherby calibers all with the velocity they produce have a true long range caliber . But everyone better get them a set of dies if you plan on shooting a lot . There is nothing wrong with that far as my aspect of looking at having a great hunting rifle . I myself enjoy the weatherby 30-378 it’s a flat shooting Caliber with a lot less recoil than most people think .

  5. .264 Win Mag is the same thing I have been shooting a weatherby Vangaurd for the last40 years the one I have was made in 1970 whats the the difference in the 6.5 -300 and the .264 Win mag both are 6.5 both are 300 cases necked down to 6.5 both are magum cases

  6. Today, I went to the beach front with my kids.
    I found a sea shell and gave it to my 4 year old daughter and said “You can hear the ocean if you put this to your ear.” She
    placed the shell to her ear and screamed. There was a hermit crab inside and it pinched her ear.
    She never wants to go back! LoL I know this is
    totally off topic but I had to tell someone!

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