6.5 CM

[6878mm]

What advantage does the 6.5CM have over any of the older 6.5s
It`s basically the same as 260rem
And of course the swedish mauser round??

[bladeracer]

What advantage does the 6.5CM have over any of the older 6.5s
It`s basically the same as 260rem
And of course the swedish mauser round??

Advantages might depend on what you're using it for.
For me, the only tangible advantage over 6.5x55mm is that if fits in a modern short-action. But if you were planning to build a target rifle then you might want to go long-action anyway to use the longest possible bullets and maximise case capacity. If you're going to use factory ammo then the Creedmoor probably has advantages in choice of bullet, availability, and cost.
The biggest advantage for me to the 6.5x55mm is the military Swedish Mausers chambered for it, they shoot great, the M38 and M96 are some of the most accurate military rifles you can find.

[Wyliecoyote]

I do own all three cartridges and all three are very capable. If buying factory ammo without any intent to reload then the 6.5 CM is the pick. If reloading there are some considerations. Factory ammo for the CM uses proprietary powders that are not available to anyone. What that means is you will not be able to safely replicate and certainly not exceed factory ammunition velocity. I have exceeded the 140 grain bullet data but that is with Alliant powders that are not currently available. Attempts to get there with ADI powders were useless and often 150 fps behind the factory CM 140 ELDM loads. The CM is very capable but not with what we can use to reload it with in Australia.
As to the other two, the 260 is in the exact same boat with ADI stuff but it will exceed the CM data if full capacity and no 2.800" magazine OAL restiction is used. The Swede exceeds both with ADI powders.
So while the hype with the CM is everywhere, when it gets to handloading, the playing field really levels out. So the Swede is my pick for its ability to get real speed with 2209 and more specifically 2213 SC as the other two haven't the boiler room to get enough of the stuff in. Accuracy is all about the time one is willing to put into it but it should never be thought that the 6.5x55 is in any way less capable than the other two.

[6878mm]

thankyou

[straightshooter]

Not withstanding any of the previous comments each of the factory headstamped cases will be manufactured with a case head temper and construction appropriate to withstand SAAMI or CIP maximum average pressures. In the case of 6.5x55 it is about 50000 PSI and the 6.5 Creedmoor it is about 60000 PSI.
That does not mean the 6.5x55 won't survive the higher the higher pressure but it does mean you are doing so on trust that it will.

[SCJ429]

I have leaned on some Lapua brand 6.5x55 brass pretty hard and achieved some pretty impressive speeds and played with a 260 AI. But the CM has a more modern case design, and given the choice it is probably the pick of the three. If it is speed you want there are plenty of bigger cases that will get you there, like the WSM or RSAUM.

[Barbarian]

As others have said, good factory offerings. Sometimes when I’m short on powder it’s good to be able to fall back on a stack of Hornady Match.

Not super steep shoulder angle is usually a good sign of it not burning up barrels super fast though not the only consideration.

Action length isn’t as much of a consideration for me because I’ve only got tikka actions.

6.5 has good bullet selection, got a pill for everything.

Also when I couldn’t find any 6.5 Creed brass it was nice being able to make it out of .308 and 7.62 brass.

[SCJ429]

As others have said, good factory offerings. Sometimes when I’m short on powder it’s good to be able to fall back on a stack of Hornady Match.

Not super steep shoulder angle is usually a good sign of it not burning up barrels super fast though not the only consideration.
.

Not sure I agree that not super steep shoulders have anything to do with burning out barrels. A 260 lasts much longer than any 243 or 22/250, despite the same shoulder angle. Big case capacity, high pressures and fast rate of fire contribute to throat erosion.

[deye243]

As others have said, good factory offerings. Sometimes when I’m short on powder it’s good to be able to fall back on a stack of Hornady Match.

Not super steep shoulder angle is usually a good sign of it not burning up barrels super fast though not the only consideration.
.

Not sure I agree that not super steep shoulders have anything to do with burning out barrels. A 260 lasts much longer than any 243 or 22/250, despite the same shoulder angle. Big case capacity, high pressures and fast rate of fire contribute to throat erosion.

Yep the bigger the caliber for a given case the longer the throat life just look at the 308w same case as a 243w 260r but a lot more life .

[Barbarian]

As others have said, good factory offerings. Sometimes when I’m short on powder it’s good to be able to fall back on a stack of Hornady Match.

Not super steep shoulder angle is usually a good sign of it not burning up barrels super fast though not the only consideration.
.

Not sure I agree that not super steep shoulders have anything to do with burning out barrels. A 260 lasts much longer than any 243 or 22/250, despite the same shoulder angle. Big case capacity, high pressures and fast rate of fire contribute to throat erosion.

The way I had it explained to me was that the more square charge from acute shoulders like in a 6dasher or 6bra compared to the more gradual shoulder angle of .308w or 6.5C lead to things like higher pressures from more complete/even powder burn which cause more erosion with all other thing being equal. "Steep" probaby wasn't the right word.

Not that that the better powder burn from those doesn't help with consistiency, but no free lunch and all.

[Wyliecoyote]

Cartridge cases are a pressure vessel, not a cylinder head exhaust port, the bullet is the plug and the bore is the gas escape vent. Pressure is pressure no matter what the case geometry might be. In bottle neck cases the shoulder angle has a direct bearing on brass flow where the steeper angle generally has less flow and vice versa. A case that has 3cc volume, no matter what its shoulder angle might be, filled with powder will produce the exact same pressure as another case of differing geometry but with the same 3cc volume. The other thing about shoulder angles is said to be that steeper angles extend throat life. I know that not to be true because the 6 Dasher destroys throats in way less than a thousand rounds as does the 7mm SAUM. A Dasher has a 40 degree shoulder angle, the parent 6BR has 30. The Dasher uses 2 grains more powder than the the 6 BR with the same bullet weight, has a 30% shorter neck yet the 6BRs life span is in excess of 5000 rounds. What greatly extends throat life is neck length and that is a given irrespective of shoulder angle. The further you can keep the heat away from the throat, the better off you are.
Where efficiency comes into play is case volume paired with the right powder burn rate. That is where the real development has been over the years with so many powders to choose from. In specific regards to the 6.5 CM with 140 grain bullets, i can fill the case with 2209, damage it after one firing, and not achieve anywhere near the velocity i can with less pressure from Alliant Reloder 26 and a case that is hardly stressed at all. So the Creedmoor case is not the efficient part, the powder used is.

[ash_hendo]

What advantage does the 6.5CM have over any of the older 6.5s
It`s basically the same as 260rem
And of course the swedish mauser round??

If you're after a new rifle, there seems to be more choice in the 6.5CM. Still seems to be enough sweds around if you're buying european rifles.

Possibly more ammo for 6.5CM and the short action thing if that's important to you.

I do like my 6.5cm, but I would have liked a 260 rem too..... just the rifles I wanted were not available in that.

[Billo]

Having owned all 3 cartridges over the last 30 years, Id probably take a lightweight 260 Rem in a short action over a swede or a CM.

[in2anity]

What advantage does the 6.5CM have over any of the older 6.5s?

The advantage? I'll tell yu the simple reality of the matter; economy of scale. Every manbunner prs shooter out there drank the koolaid, and that's a huge market.


Is it an easier cartridge to use under wind(compared with say 7.62x51)? Same as the swede; abso-f-king-lutely! Just shoot through those wind changes and think and act like you're a pro

[Jorlcrin]

I've seen a LOT of roos lose their heads from a mates .260, and it's pretty darned accurate, and pretty darned effective.
95gn V-max pills are insanely explosive on roo craniums..

Having said that; when same mate bought a rifle for his teenaged son, he chose a 6.5CM for the benefit of (roughly) similar performance from a shorter action, and the son seems to have nailed some great shots with it.

If I was re-barrelling my 7mm-08, I'd consider .260, as I dont have any short actions to take advantage of the 6.5CM OAL.
If I was buying something new, I'd be tempted to go a 6.5CM.

I guess whichever way, I'd be happy with it.

[deye243]

6.5cm and 260r use the same action.

[Jorlcrin]

6.5cm and 260r use the same action.

Yep; My Bad.
They indeed are the same action.

Cant think why I'd believed the 6.5 was shorter; vague recollection of someone talking about the benefit of the shorter bolt-throw over the .260.

But that conversation was years ago that I heard it, and obviously incorrect.

Ahhh well; you get that.

[deye243]

Yeah not that it matters I built a 260 on a long action and there was no handicap on speed or accuracy .
In fact most long range hunting rifles are built on long actions and are just as accurate as the short jobs .