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Joined: Jan 2007
Posts: 35,900
Campfire 'Bwana
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Campfire 'Bwana
Joined: Jan 2007
Posts: 35,900 |
I am closely acquainted with the people who run two of the major piezo labs, which do the pressure testing for most of the handloading powders sold in the U.S. In answer to question with a slightly different context, they told me a couple of years ago that powder capacity is THE factor in how much velocity in possible in two cases of the same caliber, loaded to the same pressure.
I specifically asked whether they'd ever found any of the magic velocity some cartridge developers claim due to shoulder angle, or how long or short a case might be. The answers from both places were an emphatic no--both adding the detail that the only factor in potential velocity is powder capacity, everything else being equal. The corollary would be that larger capacity does NOT result in less velocity when cases of the same caliber are loaded to the same pressure, regardless of case shape.
Both of those labs have been running "experiments" along those lines for many years, with state of the art pressure equipment. This makes an awful lot of sense.
The 280 Remington is overbore.
The 7 Rem Mag is over bore.
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Joined: Oct 2004
Posts: 26,678 Likes: 21
Campfire Ranger
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Campfire Ranger
Joined: Oct 2004
Posts: 26,678 Likes: 21 |
I still think you should sell that to your buddy to the West, and buy a flashy new 26 Nosler............it's SO much faster. 222, You might be able to find one of those 6.5X55 Howas at Sportsman's Warehouse. Not sure you have one close by, but Boise, perhaps would have one? And yes, I have been looking at the 26 Nosler. 264 Win, also. I just picked one up from Sportsman's for $299. That's what I paid for mine a few weeks back. Can't hardly say 'no' to that! Have you shot yours yet? If so, how did it do?
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Joined: Dec 2002
Posts: 32,243 Likes: 2
Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2002
Posts: 32,243 Likes: 2 |
I still think you should sell that to your buddy to the West, and buy a flashy new 26 Nosler............it's SO much faster. 222, You might be able to find one of those 6.5X55 Howas at Sportsman's Warehouse. Not sure you have one close by, but Boise, perhaps would have one? And yes, I have been looking at the 26 Nosler. 264 Win, also. I just picked one up from Sportsman's for $299. That's what I paid for mine a few weeks back. Can't hardly say 'no' to that! Have you shot yours yet? If so, how did it do? My Howa 1500 in 6.5x55 has a long throat, so there is a bit of freebore with lighter bullets. I shoots good, but not as good as its brothers in 6.5 Creedmoor. I like the 140 grain BT and/or Partition over H4895 in my Remington 700 Classic and Winchester/USRA 70 Fwt, but haven't found the sweet spot for the Howa yet.
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Joined: Jul 2001
Posts: 60,236 Likes: 30
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,236 Likes: 30 |
MZ5,
The reason one of the labs publishes CUP and PSI data side-by-side isn't because they're ignorant of the differences, but because SAAMI decided a few years ago to switch entirely to electronic PSI data. But so many new powders, cartridges and bullets appear constantly that pressure labs can't just retest everything in a month or two, since they're kept very busy just keeping up with new stuff. So they continue publish the CUP data, because it's still valid, even if the numbers are different.
Yes, different powders will result in different velocities in different cartridges, often enough that a "perfect" powder for a smaller round may result in slightly higher velocities than for a larger round. But that's basic stuff--that may change next week when another new powder appears that allows much higher velocities from the larger cartridge.
However, we were not discussing such powder-induced differences, but the basic overall trend in case capacity. Limited tests can also be influenced by individual barrels, which definitely can allow a smaller cartridge to reach higher velocities than a larger cartridge, but the millions of rounds and thousands of barrels used by big pressure labs would tend to even that out. Plus, there are so many powders these days that any specific advantage of one powder in a certain cartridge would almost certainly be eliminated by testing a wide variety of powders.
But since you apparently won't accept the results of two major professional labs, I'll note that Charlie Sisk, the well-known gunsmith, and I have performed quite a few experiments with his Pressure Trace that so far have confirmed their conclusions. These included rechambering the SAME barrel to different cartridges, to see what difference in pressure might result.
This was relatively easily done since Charlie's shop includes an indoor, air-conditioned benchrest room where pressure-testing (and shooting targets on an indoor 100-yard range) can be done in a controlled environment, only a few feet from his loading bench. The results of some of these tests have already been published, so I'm not going to repeat such "musings" here, but it would be relatively easy to run such test with same barrel first chambered in 6.5 Creedmoor, then rechambered to 6.5x55. However, I'm not particularly interested, since due to both the conclusions of the big labs and our own experiments, I'm sure what the results would be--and I'm sure Charlie is too.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
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Joined: Feb 2010
Posts: 15,833 Likes: 9
Campfire Ranger
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Campfire Ranger
Joined: Feb 2010
Posts: 15,833 Likes: 9 |
MZ5,
The reason one of the labs publishes CUP and PSI data side-by-side isn't because they're ignorant of the differences, but because SAAMI decided a few years ago to switch entirely to electronic PSI data. But so many new powders, cartridges and bullets appear constantly that pressure labs can't just retest everything in a month or two, since they're kept very busy just keeping up with new stuff. So they continue publish the CUP data, because it's still valid, even if the numbers are different.
Yes, different powders will result in different velocities in different cartridges, often enough that a "perfect" powder for a smaller round may result in slightly higher velocities than for a larger round. But that's basic stuff--that may change next week when another new powder appears that allows much higher velocities from the larger cartridge.
However, we were not discussing such powder-induced differences, but the basic overall trend in case capacity. Limited tests can also be influenced by individual barrels, which definitely can allow a smaller cartridge to reach higher velocities than a larger cartridge, but the millions of rounds and thousands of barrels used by big pressure labs would tend to even that out. Plus, there are so many powders these days that any specific advantage of one powder in a certain cartridge would almost certainly be eliminated by testing a wide variety of powders.
But since you apparently won't accept the results of two major professional labs, I'll note that Charlie Sisk, the well-known gunsmith, and I have performed quite a few experiments with his Pressure Trace that so far have confirmed their conclusions. These included rechambering the SAME barrel to different cartridges, to see what difference in pressure might result.
This was relatively easily done since Charlie's shop includes an indoor, air-conditioned benchrest room where pressure-testing (and shooting targets on an indoor 100-yard range) can be done in a controlled environment, only a few feet from his loading bench. The results of some of these tests have already been published, so I'm not going to repeat such "musings" here, but it would be relatively easy to run such test with same barrel first chambered in 6.5 Creedmoor, then rechambered to 6.5x55. However, I'm not particularly interested, since due to both the conclusions of the big labs and our own experiments, I'm sure what the results would be--and I'm sure Charlie is too. Only "cubes" count in an internal combustion engine. Over the last 50 years I can't come close to remembering how many articles/studies I've read that came up with the same conclusion cited by Mule Deer.
NRA Life,Endowment,Patron or Benefactor since '72.
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Joined: Jul 2001
Posts: 60,236 Likes: 30
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,236 Likes: 30 |
One of the pressure-lab guys even used the old internal-combustion standby, "There is no replacement for displacement!"
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
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Joined: Dec 2002
Posts: 32,243 Likes: 2
Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2002
Posts: 32,243 Likes: 2 |
John,
How does Hornady get a significant jump in velocity at safe working pressures with their Superformance line? Hornady claims 100 to 200 fps more speed than "standard" factory ammo.
Jeff
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Joined: Oct 2004
Posts: 26,678 Likes: 21
Campfire Ranger
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Campfire Ranger
Joined: Oct 2004
Posts: 26,678 Likes: 21 |
My Howa 1500 in 6.5x55 has a long throat, so there is a bit of freebore with lighter bullets. I shoots good, but not as good as its brothers in 6.5 Creedmoor. I like the 140 grain BT and/or Partition over H4895 in my Remington 700 Classic and Winchester/USRA 70 Fwt, but haven't found the sweet spot for the Howa yet.
How old is your Howa 6.5x55? I read a little on them and they made some dimensional changes that were supposed to help with the accuracy. That and they put a new HACT trigger in them.
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Joined: Dec 2002
Posts: 32,243 Likes: 2
Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2002
Posts: 32,243 Likes: 2 |
I bought it used on this site in 09/2015.
The SN is B2872xx if that helps any.
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Joined: Jul 2001
Posts: 60,236 Likes: 30
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,236 Likes: 30 |
Jeff,
Hornady Superformance ammo uses powders that already burn more progressively (starting out burning, then burning more rapidly as pressure rises) than most other powders, pushing the pressure peak further down the barrel.
In the factory ammo the powder is also specifically blended for a rather narrow use-range, say the .270 Winchester and cartridges of similar powder-bore ratio. They'll use another blend for the .308 Winchester and similar rounds, etc. (This is why the Superformance powder sold to handloaders doesn't result in higher velocities across the board. It's the ".30-06 blend," so won't produce the same sort of increase in, say, the .264 Winchester Magnum.)
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
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Joined: Jun 2001
Posts: 32,208 Likes: 5
Campfire 'Bwana
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Campfire 'Bwana
Joined: Jun 2001
Posts: 32,208 Likes: 5 |
That .30-06 blend ain't that bad in a .30-06.... Haven't chronographed it, but thru my 27 inch heavy barreled '98, in '06, the SuperPerfomance 150's print 6 inches high and 3 inches right of Corelokt 150's at 300 yards. Both factory ammo. I took a caribou just hours ago at a ranged 347 yards with a dead on + slightly high hold with Superperformance 150. The rifle is zeroed with that ammo at 300 and prints 3 shot groups at that range right at 1 inch, plus or minus. No, the rifle is not for sale.
The only true cost of having a dog is its death.
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Joined: Feb 2004
Posts: 12,651
Campfire Outfitter
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Campfire Outfitter
Joined: Feb 2004
Posts: 12,651 |
My money went for a 6.5-06AI.
130 Scirocco II, 3161fps with IMR 7828SSC 140g BT, 3075fps with Hodgdon H100V.
Coyote Hunter - NRA Patriot Life, NRA Whittington Center Life, GOA, DAD - and I VOTE!
No, I'm not a Ruger bigot - just an unabashed fan of their revolvers, M77's and #1's.
A good .30-06 is a 99% solution.
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Joined: Nov 2010
Posts: 37,230 Likes: 9
Campfire 'Bwana
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Campfire 'Bwana
Joined: Nov 2010
Posts: 37,230 Likes: 9 |
That .30-06 blend ain't that bad in a .30-06.... Evidently not too shabby in a 6.5 Creedmoor with 140/143 gr. bullets... DF
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Joined: Oct 2008
Posts: 1,187
Campfire Regular
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Campfire Regular
Joined: Oct 2008
Posts: 1,187 |
I was discussing the specifics of individual cartridges and asking for tested pressures & speeds, but then you and others threw estimates and generalizations into the discussion. I acknowledged time after time that the generalization is generally correct (which strikes me as kind of the definition of a generalization?), but to show me the _specific_ data. That's because to not do so is how people who don't really grasp what they're doing go and hurt themselves by disregarding tested load data and pressure limits, searching for just a little more speed. Now you've gotten lost in the generalizations and lost sight of our initial agreement and my call for either specific test data for the combo in question, or to stick with the published test data.
Concerning the lab: I refer to the publication of 2 different PSI pressure levels for a particular cartridge, not CUP vs PSI.
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Joined: Dec 2015
Posts: 13
New Member
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New Member
Joined: Dec 2015
Posts: 13 |
My money went for a 6.5-06AI.
130 Scirocco II, 3161fps with IMR 7828SSC 140g BT, 3075fps with Hodgdon H100V. I'm with you Coyote Hunter. I have shot 6.5s for years to include a 256 Newton, a standard 6.5-06, and now a 6.5-06AI. Love the 6.5-06AI so much I am have a second one built. The first is a hunting rifle, the one being built is a an F Class target rifle. Great case, easy to fire form and reload, and not a barrel burner. Delivers the velocities and accuracy I want with a 140gr bullet. Barstooler
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Joined: Feb 2007
Posts: 4,076 Likes: 2
Campfire Tracker
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Campfire Tracker
Joined: Feb 2007
Posts: 4,076 Likes: 2 |
I'll stay with the little 6.5x54 [img:center] [/img] [img:center] [/img]
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Joined: Dec 2002
Posts: 32,243 Likes: 2
Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2002
Posts: 32,243 Likes: 2 |
Do you know who "GS" was?
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Joined: Feb 2007
Posts: 4,076 Likes: 2
Campfire Tracker
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Campfire Tracker
Joined: Feb 2007
Posts: 4,076 Likes: 2 |
The only thing I don't know.The rifle was built by Austrian gunmaker Josef Mischitz and engraved by Austrian master Albin Obiltschnig.
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Joined: Nov 2010
Posts: 37,230 Likes: 9
Campfire 'Bwana
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Campfire 'Bwana
Joined: Nov 2010
Posts: 37,230 Likes: 9 |
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Joined: Feb 2007
Posts: 16,512
Campfire Ranger
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Campfire Ranger
Joined: Feb 2007
Posts: 16,512 |
MZ5. I've run several- Swedes. 260s and a -308 pre 260. Creedmoor. And a 47. Also ran a TCU but that's another story. MY Chrono confirms what Brad said. Size matters. Capacity goes up. Speed higher. Really that simple. All else equal - i.e. Bbl length - It's all in the capacity Flip a coin. Learn how to thread vitals using a proper bullet with any and carry a sharp knife. The rest is good discussion.
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