6.5 Creedmore vs 6.5 Swede

Slamfire · Dec 31, 2018

CraigC said:
That's called progress. Incremental steps forward, one at a time. Keep moving or become extinct.

It took me a while to dump the flint for those new fangled percussion caps. I also don't see much of a reason for cartridges developed after 1918, given the 30-06 covers so much, so well. Though I do have a couple of 270 Wincesters, which is an early 20's round. I purchased a 35 Whelen for no good reason at all, that is a late comer. I will concede the 308 Win is the better round for a semi automatic, though, there was no need for a 308 Win when the 7.5 X 55 Swiss would just as well.

One of these days, the Army will figure what a mistake the 5.56 was and get around to adopting a real round. I recommend: the 6.5 Swede. Low recoil, great ballistics.

The American shooter is one of the most fickle, paranoid, hypocritical and infuriating demographics extant.

Love it!

Varminterror · Dec 31, 2018

While it is true Sweden does have a long history of shooting sports, and it is true the x55 has been a player in the past (just as the now competition obsolete .30-06 and 308 win have been in the US), it’s worth noting the relative volume of firearms ownership in the US vs. their tiny number.

The US owns almost 3 times as many firearms as Sweden PER CAPITA, and en mass, owns almost ONE HUNDRED TIMES as many as a country. In other words, we’re 32 times more populous, and own 100 times as many guns... For every person who owns a gun in Sweden, there are 32 people in the US, and instead of ONE gun, they own 3... If the US mailed all of our guns to Sweden, every man, woman, and child would get 30+ firearms. How much firearms development happens in Sweden? What percentage of firearms or ammunition’s manufacturers are there? How many guys fly overseas in either direction to compete - and of those, what is the net direction? (Hint, they come here).

I’m sure there are kids in a village playing some version of soccer right now with a ball sewn from hides of animals their parents killed themselves, but we don’t talk about their techniques much in a conversation about the World Cup teams.

LRDGCO · Dec 31, 2018

You really aren't helping your case with your questions. Need a shovel?

someguy2800 · Dec 31, 2018

Varminterror said:
That’s the saddest part of the entire conversation, these threads usually go something like the below, which has lead to a thread like this one where someone reading these types of discussions is misguided into comparing a purpose designed target cartridge against a round who has had 120+ years to play in that space but has NEVER been popular for such... Just because he’s suddenly feeling inadequate when his 40yr friend is outshined by a newer penny.

OP: Hey, I’m going to buy my first rifle because I want to learn long range shooting, I’m considering 6.5 Creedmoor since I don’t reload, can someone tell me about it?

Luddite: It’s all hype. It’s exactly the same as a 120yr old, relatively unpopular cartridge I own that no one has recommended for long range shooting for 120yrs, but a lot of hunters have really loved it and Europeans have been killing moose with for generations. And this old cartridge can be handloaded to gain more speed over the Creed, so once you start reloading, you could gain a little extra speed you don’t really need. So you shouldn’t buy the 6.5 Creed.

Under-informed Fanboi screaming: The 6.5 Creed is a more modern design and is dominating long range shooting competition, it’s the only thing in the world worth owning and anyone shooting anything else is a moron!

OP - now slightly misguided: Wow, thanks for the advice, I hadn’t heard of the 6.5 Swede, should I buy that for long range? There’s a range near me which holds precision rifle matches, I might want to shoot competitions someday, would the Swede be better than the Creed for that?

Under-informed Fanboi again: the modern design of the 6.5 Creedmoor was specifically developed for long range precision shooting, and it’s dominating every match in the country. The Swede would have to be reloaded to beat the Creed, and the Swede burns barrels faster.

Luddite: I’ve hunted with the 6.5 Swede my entire life, I don’t shoot much, just hunt, so I won’t ever burn out my barrel.

Other Luddite: If you already own a 308win or other deer rifle, you can learn with that without wasting money on the new hype. Ammo is cheaper and more readily available, and it won’t burn out barrels as fast as the 6.5 creed.

OP - now confused and even more misguided, and turned off of the 6.5 creed by the spewing fanboi: Wow, ok, this would be my first rifle, but if the 6.5 costs that much to shoot and burns barrels that fast, maybe I SHOULD get something else. What rifle should I get for long range shooting and eventually competition, I’ve been looking at a Ruger Precision Rifle or Savage 110 BA Stealth, are they good, which one?

Yet another Luddite: Any budget friendly rifle will be able to shoot 1,000yrds, you don’t need to buy one of these new spaceship looking rifles. So save yourself some money and pick up a Ruger American or Savage Axis.

OP - unwittingly lead like a lamb to the slaughter: thanks for the advice everybody, I’m glad I asked instead of buying the wrong thing.

*Replace any occurrence of the 6.5 Swede with analogous comparison of the 260rem.

So enough of those threads go around and this guy who has enjoyed his Swede for 40 years develops an inferiority complex about his beloved 6.5 Swede and is compelled to post questions online to get reassurance his old rifle is still relevant for how he’s using it...

You forgot all the post about how both are stupid and you should get a 7mm-08, a 35 whelen, or a 218 bee.

Legionnaire · Dec 31, 2018

Tagging in. I want to be able to reference Varminterror’s all-too-frequent “hypothetical” conversation.

... and for the record, make mine a .260!

denton · Dec 31, 2018

Gtscotty said:
The velocities you quoted are within 20-30 fps of published Alliant maxes for the same bullet weights in the Creedmoor. Are you saying that bullets heavier than those are where the Swede pulls ahead? What velocities are you getting for full power loads in the 140gr and 150gr weight classes?

I habitually look at the Hodgdon data, which isn't quite as zippy as the Alliant data. Good observation! Thanks for mentioning it.

The 6.5x55 has about 10% more case capacity than the 6.5 CM. John Barsness' rule on case capacity is that for every 1% increase in capacity, you get about 1/4% increase in MV. So in round numbers, you should be able to add about 70-75 FPS to any published 6.5 CM velocities with the bigger case if you're running the same bullet, powder, and pressure. It's a pretty good rule that heavier bullets take more of a toll on MV with smaller case capacity.

I was having some problems with my modern 6.5x55, and while working on it, the gunsmith destroyed the strain gauge mounted on it. By the time that happened, I only had data for the lighter bullets. So I don't have measured data for the heavier bullets.

The difference in performance is more or less just a point of curiosity for me. I'm not willing to walk more than 200 yards to pick up a dead animal, and that simplifies my life considerably.

Llama Bob · Dec 31, 2018

denton said:
The 6.5x55 has about 10% more case capacity than the 6.5 CM. John Barsness' rule on case capacity is that for every 1% increase in capacity, you get about 1/4% increase in MV. So in round numbers, you should be able to add about 70-75 FPS to any published 6.5 CM velocities with the bigger case if you're running the same bullet, powder, and pressure. It's a pretty good rule that heavier bullets take more of a toll on MV with smaller case capacity.

Except of course that the design of the respective cartridges doesn't lead to the same max pressure. The high taper of the x55 case doesn't like it, and small primer brass in the 6.5CM is a substantial advantage in terms of pressure tolerance.

The extra case capacity of the x55 is more than lost back in low pressure and shoulder inefficiency. If you went 6.5x55 AI it would pull ahead, but once you go to a wildcat (and a long-action one at that) you're looking at a different set of competitors (like the 6.5-06 AI and even the .264WM and 26 Nosler) and the x55 doesn't compare well there either.

denton · Dec 31, 2018

Llama Bob said:
Except of course that the design of the respective cartridges doesn't lead to the same max pressure. The high taper of the x55 case doesn't like it, and small primer brass in the 6.5CM is a substantial advantage in terms of pressure tolerance.

The extra case capacity of the x55 is more than lost back in low pressure and shoulder inefficiency. If you went 6.5x55 AI it would pull ahead, but once you go to a wildcat (and a long-action one at that) you're looking at a different set of competitors (like the 6.5-06 AI and even the .264WM and 26 Nosler) and the x55 doesn't compare well there either.

Hmmmm.... having a little trouble with these statements.

For all practical purposes, the 6.5x55 shares its case head geometry with the 30-06 (60 KPSI), the 308 (62 KPSI), the 25-06 (63 KPSI) and the 270 (65 KPSI). The 6.5 CM, with the same rim diameter, is rated at 62 KPSI, right in the middle of the pack. I'm not convinced that the smaller primer pocket confers any practical advantage in pressure containment. The 270 seems to get along pretty well with large primers.

The efficiency of a rifle in converting gas pressure energy to bullet kinetic energy is almost entirely determined by basic thermodynamic efficiency, which is the difference between the peak temperature and the gas temperature at bullet exit, divided by the gas temperature at bullet exit. I may be overlooking something, but I've never seen anything beyond conjecture that connects shoulder angle to conversion efficiency. Another way of saying it is that it all boils down to the expansion ratio, case capacity vs. volume of case capacity plus bore volume.

Llama Bob · Dec 31, 2018

denton said:
Hmmmm.... having a little trouble with these statements.

Taper matters. Primer size matters. Shoulder efficiency matters. You can think what you want, but there's a reason the the x55 only appears in any venues where performance matters in some sort of improved wildcat form (and rarely then).

And shoulder angle and size has everything to do with efficiency. Energy spend accelerating unburned powder (and eventually resulting in higher gas velocities after bullet exist) is energy wasted. The bigger and steeper the shoulder, the less powder travels down the barrel and the less energy is wasted. The ideal cartridge would keep all the powder in the case and only vent gas down the barrel. Unfortunately that's not possible, but some cases do much better than others. All this was originally discovered a long time ago when working out the ballistics of cannons by a french balistician named Sebert. Cannons, lacking a shoulder entirely, have a very dramatic version of this effect, as do straight wall rifle and pistol cartridges.

rust collector · Dec 31, 2018

I understood that SAAMI spec for the 6.5 Creedmoor was for large rifle primers. Lapua started producing small primer brass and other suppliers now make that an option.
If there is a standard pattern for maximum efficiency, why don't all cartridges conform? Why not use bottleneck cases for artillery, if that improves velocity? I'm not taking issue with your statements, but just curious, I guess.

Walkalong · Dec 31, 2018

It's easier to build and maintain more pressure with less powder in an overbore case vs a straight walled case.

rust collector said:
Why not use bottleneck cases for artillery, if that improves velocity?

I would assume ease of function and dependability, and they don't need it. Much easier to make rimmed cases fit a straight chamber with no headspace/function issues etc. I have no clue, but that is my guess.

Llama Bob · Dec 31, 2018

rust collector said:
If there is a standard pattern for maximum efficiency, why don't all cartridges conform? Why not use bottleneck cases for artillery, if that improves velocity? I'm not taking issue with your statements, but just curious, I guess.

Almost all new cartridges do. It took quite a while for the information to get widely known - perhaps in part because the original source was in French, not in English and on the surface applied to cannon rather than personal arms. People like P.O. Ackley and Roy Weatherby were really the re-birth of shoulder efficiency in the US.

I don't claim to be an expert on artillery or naval guns, but from a ballistics POV a chamber with a shoulder would definitely help them - effectively reduce the "weight" of the projectile by about 1/4 the weight of the powder charge. On something like a 16"/50 naval gun that would work out to about a 6% increase in energy for the AP projectile with no change in powder. However, I can see lots of mechanical, space, maintenance and weight reasons not to do that.

Walkalong · Dec 31, 2018

Llama Bob said:
However, I can see lots of mechanical, space, maintenance and weight reasons not to do that.

Kind of what I was thinking. Too much trouble for too little gain, and maybe less dependable.

rust collector · Dec 31, 2018

Makes sense to me. Then I look at images of current competition cartridges, and there seems to be different theories regarding shoulder angles, taper and the like. http://www.6mmbr.com/compcartridges.html Roy Weatherby's dual radius shoulder doesn't seem much in evidence, but I recognize that some designs are more by accident than by calculation (such as 50 bmg being a scaled-up 30-06 at Pershing's insistence). All fascinating to me.

Llama Bob · Dec 31, 2018

Walkalong said:
Kind of what I was thinking. Too much trouble for too little gain, and maybe less dependable.

There's also a question of payoff. In a personal arm, improving the shoulder is like a free lunch in terms of recoil - you get say a 1% speed increase and 2% energy increase (going from say a .30-06 shoulder to an 40 degree AI shoulder) without any increase in recoil because at the same time you're speeding up the projectile, you're slowing down the gas and both cause recoil. As long as the new shoulder doesn't have feed problems, you got something for nothing. it's not a big change, but who doesn't like free stuff?

In an artillery piece, recoil is less of an issue so if you want more horsepower you can just make the chamber longer (to control pressure), add powder, and reduce the burn rate of the powder and voila - more velocity. And you can go essentially as far down that road as you want keeping in mind bore erosion.

Llama Bob · Dec 31, 2018

rust collector said:
Makes sense to me. Then I look at images of current competition cartridges, and there seems to be different theories regarding shoulder angles, taper and the like. http://www.6mmbr.com/compcartridges.html Roy Weatherby's dual radius shoulder doesn't seem much in evidence, but I recognize that some designs are more by accident than by calculation (such as 50 bmg being a scaled-up 30-06 at Pershing's insistence). All fascinating to me.

I would say that competition has more or less settled on a fairly wide 30-40 degree Ackley-type shoulder. The issue is getting there, since many cases have to be fire or hydroformed to make it happen. Combine that with the wide range of optimal shoulder positions depending on projectile length, and you get the proliferation of wildcats seen on that page.

For newer cases - Creedmoors, .284 Win derivatives, PPC, x47 Lapua, WSMs, SAUMs, Nosler, Dasher, Valkyrie, PRC etc. - they all follow the formula. It's P.O. Ackley's world now - we just shoot in it

Archie · Dec 31, 2018

I have six "Swedish" (Mauser 1891 action) rifles which started out as M1894 or M1896 rifles. Some have been 'altered' to serve as hunting rifles. They are chambered for 6.5x55mm (Swedish Mauser).

It is a really useful cartridge, especially considering it was designed and first used over a century ago. The 160 grain bullet is the original loading (actually 10.1 grams or 156 grains in the 'metric' loading). That heavy for weight bullet has more sectional density than a 220 grain .308 caliber bullet. It has momentum and penetration ability.

One problem I have with the 6.5 Creedmore or Grendel is there is no loading information for the heavy bullet. Also, I do not know if the rifles so chambered have enough room in the leade for such bullets loaded normally.

If I had to update, I would prefer the .260 Remington, as it has roughly the same powder capacity and it fits a 'standard' (8x57mm Mauser, .30-06 Springfield, .308 Winchester and a multitude of adaptations) head size. The only problem is the .260 Remington has a twist too slow to stabilize the heavy bullets. Seems the brain trust at Remington decided no one would shoot any bullet larger than 140 grains. So I would need a custom barrel.

No. My needs are well covered and I don't see the need to spend more money on something that doesn't do anything I cannot do now and will not do what I want it to do. I'll stick with Olle.

Varminterror · Jan 1, 2019

Llama Bob said:
Except of course that the design of the respective cartridges doesn't lead to the same max pressure. The high taper of the x55 case doesn't like it, and small primer brass in the 6.5CM is a substantial advantage in terms of pressure tolerance.

The extra case capacity of the x55 is more than lost back in low pressure and shoulder inefficiency.

None of this has been my experience in running x55 for about 20yrs. I wasn’t running to 6.5 Creedmoor pressures back then since the Creed didn’t exist, but rather to .30-06 pressures - which is what my donor action had tolerated before conversion. Let’s call it close enough to be trading nickels...

The Swede brass does grow. I’ve counted myself happy any time brass runs over a dozen loadings, and I have taken some x55 past 20 loadings.

Not all 6.5 Creedmoor brass is small primer either. Nor are the 6.5-284 and 6.5 A-Square... I do tend to agree, if you’re going long action just to get 150fps, you might as we go clear out to full length and pick up a LOT of bullet weight and speed too - at least until you start remembering how few rounds the 6.5-284 barrels last, and 6.5-06 Improved even less.

Your theoretical math on recoil reduction by Ackley-izing shoulders doesn’t hold up in real world performance either. As you blow out the case, it takes more powder to stay at your old velocity, as the pressure generated by the load is lower (larger volume, same mass of propellant, lower pressure. Simple, right?). So to stay at the same speed with the Ackley’s, you have to pump a little more powder - and in a very real, but insignificant and largely unnoticeable amount, the recoil increases. The burn efficiency doesn’t keep up with the increase in volume, so you lose speed by increasing case volume if you don’t add more powder. Same exact paradigm as 308win and 30-06 - more powder in the long case to reach the same speed. The pressure is lower at the same velocity performance level, but it takes more powder to get there after you blow out the Ackley shoulder. That’s not to say it’s not VERY nice to halt brass growth, and not at all meant to thumb my nose at Improving cartridges, ‘Lord knows I’ve done a bunch and love the practice, but it’s not a magical design which defies the laws of physics.

And to the rabbit hole of bottlenecked artillery pieces, I think there’s a fundamental difference in what we want/need these projectiles to do, but in a very real sense, when you neck down the only way out, your pressure climbs, meaning your bolt thrust climbs. But your resulting momentum on target, resulting from the potential energy converted from your powder charge, is significantly reduced when you start trading projectile weight for speed. So more damage on the good-guy end, and less damage on the bad-guy end, pretty simple algebra to me.

Llama Bob · Jan 1, 2019

Varminterror said:
Your theoretical math on recoil reduction by Ackley-izing shoulders doesn’t hold up in real world performance either.

Maybe you didn't mean it that way but I find statements like this to be somewhere between absurd, ignorant, and insulting. The impact of Sebert's factor on interior ballistics has been well understood at least in some circles for 120+ years, and now you've decided to come along and claim it just doesn't matter in your world because, what, you're special? What other laws of physics do you think don't apply to your gun? You seem like an otherwise good guy, but this is ridiculous. Sebert's factor isn't "theoretical" - it's how your gun works. It's no more theoretical than Newton's laws. In order to understand the movement of the projectile, you have to add some fraction of the propellant weight to the bullet weight to account for the powder flying down the barrel with it. Otherwise you will get the wrong answer. The better the shoulder, the less you add and the "lighter" the projectile+powder is and the faster it goes.

As a rough guide to what fraction of the powder has to be added to the bullet weight
40% - highly improved small bores like the 6mm Dasher
45% - improved small bores like the WSMs
50% - "typical" shoulders like the .308
55% - old high slope shoulders like the .30-06
60% - really high slope shoulders like the .300 H&H
65% - ghost shoulders like the .375 H&H
70% to 75% - straight wall (depending on taper)

You can look at your case and see where it falls on the chart.

The math is fairly simple: say you've got two cases, same case capacity both 60gr of whatever powder you're using, but one has a WSM type shape and one has a .30-06 type shape. You're shooting a 150gr bullet out of both. Now, the first case will have 150gr of bullet plus 27gr of powder traveling down the barrel. The 2nd will have 150gr of bullet plus 33gr of powder. That extra 6gr of powder is dead weight and increases the total weight of the projectile+powder by 3.4%. That energy is simply lost - it manifests as wind out the barrel behind the bullet, producing recoil but not velocity. The net result will be that the less efficient case propels the bullet about 1.7% slower for the same powder, same pressure, and same recoil.

For AI calibers this benefit is in addition to any benefit from extra case capacity from blowing out the shoulder.

The comparison between the 6.5CM and 6.5x55 isn't quite so simple because they also have a difference in case capacity, but the x55 is paying a similar bad shoulder tax.

someguy2800 · Jan 1, 2019

aaaand we're done here.

Varminterror · Jan 1, 2019

I’d love to pretend the velocity data I see blowing out BR’s to Dashers, blowing out 223’s, 243’s, 25-06’s, the very 6.5 Swede we’re discussing here and the sister 7x57, 30-06’s, and 7-08’s didn’t exist.

But in working up all of these rifles, I have never had a single one of them run faster with the same powder charge after fireforming than a standard chamber. More powder to get back to the same speed.

Yes, every grain added yields better performance with a steep shoulder than a sloped shoulder, but there are no free lunches. Once you blow out the shoulder, you’re adding powder to get back to the same velocity.

Comparatively, pushing back a 6 SLR (curiosity got the cat, regrettably) and running almost identical capacities as 243win, it’s easy to get to the same speed with less powder and ostensibly lower pressure.

Sure seems odd that SAAMI chooses to ignore the neglected ejecta mass game and runs full mass, with a scalar for ejecta velocity... sure seems odd they’d follow fundamentals of physics and respect the full momentum of the system... I prefer to not pretend less mass is exiting my barrel than actually is.

Llama Bob · Jan 1, 2019

Varminterror said:
But in working up all of these rifles, I have never had a single one of them run faster with the same powder charge after fireforming than a standard chamber. More powder to get back to the same speed.

You're changing two variables (shoulder efficiency and case capacity) and mixing up what's causing what.

In order to see the effect of shoulder efficiency alone, you have to have two cases with the same capacity and different shoulders (so for example shoulder pushed back slightly on the AI case). Then you will see more velocity for the same powder charge and pressure.

someguy2800 · Jan 1, 2019

Well by golly its your lucky day because the 260 rem and 6.5 CM happen to have 1 grain difference in case capacity and a 20 degree vs 30 degree shoulder angle. So if there is an advantage of velocity vs charge weight to be found we ought to see it their right?

midland man · Jan 1, 2019

LOL well okay so I wonder how my 243 win with 100gr bullets compares to these two cartridges the 6.5x55 and the 6.5CR it sure seems like the 243 with 100gr bullets kills and goes along way as far as distance goes!

Llama Bob · Jan 1, 2019

someguy2800 said:
Well by golly its your lucky day because the 260 rem and 6.5 CM happen to have 1 grain difference in case capacity and a 20 degree vs 30 degree shoulder angle. So if there is an advantage of velocity vs charge weight to be found we ought to see it their right?

If you've got cases that in fact have the same capacity, then yes, you'll see extra velocity out of the steeper shoulder with the same charge weight, pressure, seating depth, barrel length etc. Should be about 20 ft/s (QuickLoad estimates 19 ft/s for one combination I cooked up).

In order to do the experiment correctly though a pressure test setup is required - ideally a piezo sensor - to ensure pressure is the same and you may have to adjust charge weights slightly to compensate. Otherwise differences in chamber volume could easily sabotage the whole thing.

6.5 Creedmore vs 6.5 Swede

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