6.5 Millimeters of Magic - Outperforming Since Bismarck

[Talyn]

It is impossible, 140 years later, to say exactly who first concluded that a bullet of 6.5mm diameter, .264 in imperial measure, was the perfect caliber for a rifle.

It is also almost impossible to explain why it took Americans so long to agree. By 1905, 6.5mm cartridges were standard at every level in Europe; not until a century later, in 2007, did a 6.5mm rifle conquer the American heart and become the rifle everyone wanted.

6.5 Millimeters of Magic | Handloader Magazine

www.handloadermagazine.com

Typical military 6.5s from around 1900: (1) 6.5x50 Arisaka, (2) 6.5x52 Carcano,
(3) 6.5x54 Mannlicher-Schönauer, (4) 6.5x53R Dutch, (5) 6.5x55 Swede and (6) 6.5x58 Mauser.

A range of modern civilian 6.5s: (1) 6.5 Grendel, (2) 6.5 Creedmoor,
(3) 260 Remington, (4) 6.5x55, (5) 6.5-284, (6) 264 Winchester Magnum
and (7) 26 Nosler.

 

[Pitdogg2]

Barrel life may have been the contributing factor why the military moved away from 6mm-6.5mm.

 

[Talyn]

Barrel life is fine except for those 6.5's like the 264 Win Mag, 26 Nosler & 6.5x284.

It's all about how hard you push things (case volume) in relation to the specific bore diameter. P.O. Ackley called it the "Over-bore" effect.

P.O. Ackley: Man of Sharp Shoulders - Sporting Classics Daily

“That’s gone. It sold right away. Sorry.” I had phoned on an ad for a rebarreled Mauser. He did sound genuinely sorry. My reply—“Oh,”—must have had an authentic ring, too. I truly was crushed. “You wouldn’t want a Springfield, would you?” As if he owed me something. He spooled out details that...

sportingclassicsdaily.com

Barrel life issues also applies to other calibers that have cartridges that are "over-bore".

More from this topic in a discussion early on here.

Thread '“Overbore” — A Practical Definition by the Numbers'

Sep 26, 2020

P.O. Ackley all ways talked about "Overbore" when he developed his Ackley Improved versions.

“Overbore” — A Practical Definition by the Numbers

• Talyn
• Replies: 7
• Forum: Guns

• 

“Overbore” — A Practical Definition by the Numbers « Daily Bulletin

What is Overbore? That's a question rifle shooters can debate to no end. This article from our archives proposes one way to identify overbore cartridges. We think the approach outlined here is quite useful, but we know that there are other ways to define cartridges with overbore properties.

bulletin.accurateshooter.com

Practical Tips to Extend Barrel Life

With the number of “overbore” rifle cartridges popular today, barrel erosion is becoming a hot topic...

precisionrifleblog.com

 

[Anchorite]

That list needs the 6.5 RPM, 6.5 PRC and 6.5 Grendel!

 

[USMC6094]

6mm Lee was was a barrel smoker, and was replaced by 30-40 Krag.

6.5, 7mm, have done it ALL, and killed it ALL.

I wish I'd discovered 6.5 Swedish long before I did.

Eventually I'll get a Creedmoor .....