6.5 Creedmore vs 6.5 Swede

[eastbank]

good news, 700 Remington SA sps in .260 has a 1-8 twist and a 24" barrel. good news for the long heavy bullet fans. I know I,m not going to win any 1000 yards matches, but its a great mid range hunting-target rifle. with a 24" barrel and 1-8 twisted .260 just how much better will the 6.5 cm be? will the shoulder angle(only difference) make any real difference in over all prefomence between the .260 R and the 6.5 CM.

 

[Sky Dog]

I don't that much about the Creedmore, but I've shot a Swede for the past 40 years. I know the Swede's potential is not realized due to the older mauser actions. Would a modern action with optimized reloads be comparable?

I have enjoyed this rifle for better part of my life. My grandfather sporterized it back in the 30's. I want to leave it to my nephew while the barrel is still in good shape. I have dies, hundreds of cases, and 3 generations of reloading recipes. I'd like to replace it for myself with another 6.5mm. The reason for posing the original question is whether or not the Creedmore is that much better than the Swede. Enough so to reinvest in a new cartridge

 

[Walkalong]

Beautiful rifle.

 

[Nature Boy]

That’s what this thread needs: more pics

 

[Sky Dog]

Beautiful rifle.

Thank You!

 

[Sky Dog]

That’s what this thread needs: more pics

Absolutely!

 

[Varminterror]

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.

Reading...

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.

But in the context of this 6.5 creed vs. Swede thread, the statement of your original argument - aka, where you noted the 6.5 Swede’s low efficiency shoulder and body taper mean it can’t be loaded to the same pressure, stating it must be blown out to AI to match the Creed, and state the AI shoulder will make more from less for the Swede remain to be patently false. Been there, loaded that, didn’t just read about it...

 

[Legionnaire]

Sky Dog, that’s beautiful. I’ve got my eye open for a Ruger No.1 RSI in 6.5 Swedish. Love the look of the Mannlicher stock.

 

[Llama Bob]

Reading...



But in the context of this 6.5 creed vs. Swede thread, the statement of your original argument - aka, where you noted the 6.5 Swede’s low efficiency shoulder and body taper mean it can’t be loaded to the same pressure, stating it must be blown out to AI to match the Creed, and state the AI shoulder will make more from less for the Swede remain to be patently false. Been there, loaded that, didn’t just read about it...

Nope, it's clear that you failed to understand what I said. The pressure issue is the taper and if you want to hot rod primer pocket. The efficiency issue is the shoulder.

The 6.5x55 is crippled by 19th century design decisions that will leave it forever behind the 6.5CM both at SAAMI pressure and hot rodded despite being slightly larger. In AI form it's faster, but still stuck in a long action and falls far behind other LA wildcats. No matter which way the 6.5x55 turns, it compares poorly. That's why it's been killed by the Creedmoor.

 

[midland man]

like I said my 243win with sierra 100gr bullets performs very well I bet it will whoop the 6mm creedmore!!

 

[rust collector]

I love the pictures of the old Swede. Sky Dog, your grandfather did a fabulous job on that old warhorse, and I hope your nephew can appreciate it.
One of my newer Swedes is a Husqvarna 8000 which wears a pac-nor barrel. I could load hotter for it, but as long as I have older models around I stick with only a slightly warmer load. Also have a CZ 550 full stock in 6.5 x 55, but haven't played with it much. The x55 brings home the meat, and the Creedmoor has an advantage on targets. All good.

 

[eastbank]

with several thousand .308 match once fired cases(free) on hand to make into 243-260-7mm08, please tell me what I might gain by buying a 6.5CM over my 260 Remington 700 short action sps with a 1-8 twist and 24" barrel ran at the same pressure. surly not the cost of cases, with bullets-powder- primers,so close it don,t matter and over all preformence closer than a sheet of very thin paper. my 6.5x55,s run from swede military rifles to a Remington 700 classic and a CZ-550 and my 260 rem,s are a browning 1885 low wall, a remington 7600 pump and a Remington 700 sps.

 

[Sky Dog]

I love the pictures of the old Swede. Sky Dog, your grandfather did a fabulous job on that old warhorse, and I hope your nephew can appreciate it.
One of my newer Swedes is a Husqvarna 8000 which wears a pac-nor barrel. I could load hotter for it, but as long as I have older models around I stick with only a slightly warmer load. Also have a CZ 550 full stock in 6.5 x 55, but haven't played with it much. The x55 brings home the meat, and the Creedmoor has an advantage on targets. All good.

I'm looking at the CZ550. Tikka and Sauer 100. I don't know of any other manufacturer's except for Ruger. btw, thanks for the Kudo's. Grandaddy would appreciate it.

 

[Sky Dog]

Sky Dog, that’s beautiful. I’ve got my eye open for a Ruger No.1 RSI in 6.5 Swedish. Love the look of the Mannlicher stock.

Thanks for the kudos. I always thought mannlicher and 6.5x55 were a perfect match. Note the Springfield mod on the bolt.

 

[Gtscotty]

with several thousand .308 match once fired cases(free) on hand to make into 243-260-7mm08, please tell me what I might gain by buying a 6.5CM over my 260 Remington 700 short action sps with a 1-8 twist and 24" barrel ran at the same pressure. surly not the cost of cases, with bullets-powder- primers,so close it don,t matter and over all preformence closer than a sheet of very thin paper. my 6.5x55,s run from swede military rifles to a Remington 700 classic and a CZ-550 and my 260 rem,s are a browning 1885 low wall, a remington 7600 pump and a Remington 700 sps.

If you have a .260 with a fast twist and long mag box, I don't think anyone is telling you to sell it and buy a 6.5 Creed. For those who are looking to buy a medium power 6.5mm rifle and don't already have a .260, there aren't really any good reasons to choose that route over the Creedmoor. There may be good personal reasons to choose the Swede over the Creedmoor like nostalgia, classic rifle options, milsurps, etc.

 

[CraigC]

If you have a .260 with a fast twist and long mag box, I don't think anyone is telling you to sell it and buy a 6.5 Creed. For those who are looking to buy a medium power 6.5mm rifle and don't already have a .260, there aren't really any good reasons to choose that route over the Creedmoor. There may be good personal reasons to choose the Swede over the Creedmoor like nostalgia, classic rifle options, milsurps, etc.

What he said. Most .260's aren't configured that way. The 6.5CM is right out of the box.

 

[Gtscotty]

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'm not sure that the basic thermodynamic envelope look at the system is very instructive when it comes to the amount of useful work done on the bullet itself. I think looking it as pressure-volume work is probably more useful for examining effects on the bullet, which is really all we care about. The bullet only really cares about the force it sees on its base minus the drag force of the barrel interface, and whatever inertial force is exerted by the air in the barrel being forced to move by the bullet (probably pretty small).

To get a view of the whole, you'd probably be looking at something like the integral of the force curve at the base of the bullet (product of pressure and area) minus the integral of the barrel drag force curve (both with bullet barrel time on the X). Or something like that, too lazy to crack the books on my day off. At any rate, I could see how geometric changes to the powder burning chamber might affect flow during combustion, rate of combustion, and therefore the pressure curve as experienced by the bullet.

 

[Random 8]

Sky dog, beautiful rifle. Color me jealous. In response to your original question, with follow up information you have given, I can see two routes, both make sense.
1. My pick. Get a rifle in 6.5CM, and invest in a die set and brass. Assuming hunting applications. This will give zero chance of mixing up high pressure loadings with the old M96 action (will a 6.5 CM chamber in a 6.5x55 chamber? IDK, but assume you're smarter than that), piece of mind is important. Most of the bullets and powders you love in the X55 will serve you well in the Creed as well.
2. Get a European rifle or a used American model in 6.5x55 and be extremely careful not to cross 6.5SE ammo with "old gun" ammo. In my opinion, there is little practical performance difference in 6.5SE and 6.5CM for your purposes in a light to medium game rifle. As you're already heavily invested in the 6.5 round, procuring brass and useful loading data should present little problem.

 

[denton]

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I have enjoyed this rifle for better part of my life. My grandfather sporterized it back in the 30's. I want to leave it to my nephew while the barrel is still in good shape. I have dies, hundreds of cases, and 3 generations of reloading recipes. I'd like to replace it for myself with another 6.5mm. The reason for posing the original question is whether or not the Creedmore is that much better than the Swede. Enough so to reinvest in a new cartridge

OK, let me take one more whack at contributing to your deliberations...


(Somebody wanted more pictures. So here is one. Oh. You meant gun pictures? )
Here is what QuickLoad thinks each cartridge will do, loaded to 60 KPSI. This wasn't an exhaustive search for the optimum powder. I limited the field to Hodgdon powders, simply out of convenience. In each case I made apples to apples assumptions for seating depth, case capacity, etc.

For each bullet weight, the 6.5x55 exceeds the MV of the 6.5 Creedmoor, but not by enough to write home about.

I think what it boils down to is this: If you want top MV with SAAMI or CIP pressure specs, or if you want something that will work in an AR platform, then the 6.5 CM is the clear winner. If you already have a 6.5x55, want to stick with a bolt action, and either don't mind loading to the 6.5x55's potential or don't care that much about breaking speed records, switching to the CM isn't going to buy you much. Only you can decide what you value.

Llama Bob is a credible contributor to the forum, and he clearly believes what he's posted. And maybe he's right. But I haven't yet seen anything that convinces me that case geometry makes any difference in MV. The sources I've read all say it boils down to case volume, bore volume, and bullet mass.

 

[Llama Bob]

To get a view of the whole, you'd probably be looking at something like the integral of the force curve at the base of the bullet (product of pressure and area) minus the integral of the barrel drag force curve (both with bullet barrel time on the X). Or something like that, too lazy to crack the books on my day off. At any rate, I could see how geometric changes to the powder burning chamber might affect flow during combustion, rate of combustion, and therefore the pressure curve as experienced by the bullet.

That's basically how you do it - path integral of force on the base of the bullet minus drag forces through the length of the barrel is the final energy. However the "bullet" is the actual bullet plus some additional weight for powder traveling down the barrel. There's a bit more to the mechanical model at the beginning to - the force required to overcome neck tension/crimp and then engrave the bullet onto the lands. Until you overcome that, there's no movement.

The shape of the chamber really only matters in practice in terms of how much it retards powder moving down the barrel. Other than that issue, case capacity is case capacity.

Of course there's also a powder burn model that says how the powder will burn as a function of pressure and time. The pressure is controlled by the gas released and the expanding chamber behind the bullet.

Combine those two models and a numerical integrator and you get Quick Load.

 

[cdb1]

I ran in to this guy at the range today and decided to ask him the question, 6.5 Creedmoor vs 6.5x55. He gave me a blank look and never stopped shooting.


If you strictly hunt like I do it matters not one whit which cartridge you use. Cartridge choice should depend on esoteric values. If you’d rather have a Willys Wagon than a Land Cruiser get a Swede. If you’d rather have a Land Cruiser get a Creedmoor. I’d rather have a Willys Wagon so even if I didn’t already have a Swede in a modern action before the Creedmoor craze I’d still opt for a Swede today.

If I were a long distance target shooter there’s no question I’d have a 6.5 Creedmoor for a myriad of obvious reasons.

Post #46 by Varminterror is a beautiful thing.

I did a little reading on the subject of 6.5x55 on alg in Scandinavia a year or so ago. While in the past it was the number one cartridge used it was superseded a while back by a number of other cartridges.

 

[Walkalong]

I ran in to this guy at the range today

He absorbs recoil well.

 

[cdb1]

I thought so.

 

[CraigC]

He absorbs recoil well.

Mass is everything!

 

[denton]

I'm not sure that the basic thermodynamic envelope look at the system is very instructive when it comes to the amount of useful work done on the bullet itself. I think looking it as pressure-volume work is probably more useful for examining effects on the bullet, which is really all we care about. The bullet only really cares about the force it sees on its base minus the drag force of the barrel interface, and whatever inertial force is exerted by the air in the barrel being forced to move by the bullet (probably pretty small).

To get a view of the whole, you'd probably be looking at something like the integral of the force curve at the base of the bullet (product of pressure and area) minus the integral of the barrel drag force curve (both with bullet barrel time on the X). Or something like that, too lazy to crack the books on my day off. At any rate, I could see how geometric changes to the powder burning chamber might affect flow during combustion, rate of combustion, and therefore the pressure curve as experienced by the bullet.

Good point, but one of the major energy losses is when the bullet uncorks the barrel and all the energy left in the compressed propellant gas is lost. Lower pressure and temperature at exit, more efficient conversion, all other factors equal. So it's still instructive.