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Discussion Starter #1
Cartridges like the PRC and Creed have steep shoulders, like the AI cartridges. If you gave the .264 WM a 30 degree shoulder, would it also improve speed, and efficiency?

What if the 6.5 Rem Mag had the steep shoulder, would it have got a foothold in the market ?

Wouldn't a .260 AI be better than the CM ? If all other things are equal, excusing the long throat of the Creed.

Darky isn't this right up your alley?
 

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Cartridges like the PRC and Creed have steep shoulders, like the AI cartridges. If you gave the .264 WM a 30 degree shoulder, would it also improve speed, and efficiency?

What if the 6.5 Rem Mag had the steep shoulder, would it have got a foothold in the market ?

Wouldn't a .260 AI be better than the CM ? If all other things are equal, excusing the long throat of the Creed.

Darky isn't this right up your alley?



Most things have been done.


https://shermanwildcatcartridges.com/online-store?olsPage=products
 

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The Hog Whisperer (Administrator)
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Sure, burn out barrels even faster with an 'improved' .264 Win Mag.... why not? :p
 

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If you gave the .264 WM a 30 degree shoulder, would it also improve speed, and efficiency?
?
I dare say that there is a difference between what "efficiency" means in terms of internal thermodynamics and what shooters attach to the term. There will be no improvement in efficiency.
 

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Discussion Starter #5
If you gave the .264 WM a 30 degree shoulder, would it also improve speed, and efficiency?
?
I dare say that there is a difference between what "efficiency" means in terms of internal thermodynamics and what shooters attach to the term. There will be no improvement in efficiency.
They credit the Creed's accuracy to its 30°(or is it 35°) shoulder. Supposed to give a more consistent burn when packed in the short-fat cases. Like the 6.5 Creed is supposed to match speed with the .260, but do it with less powder.....more efficient.
 

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Most of the advantage offered by Ackley Improved cartridges comes from less body taper, which necessitates a steeper shoulder to achieve the same headspace (datum line on the shoulder). If you look at all of the more successful AI cartridges, they started out with a shallow shoulder angle, yes, but the main thing was they all had a whole lot of case taper. There just isn't much left on the 264WM or the 260 Remington to "improve". They're both of reasonably modern case design.

Keep in mind that much of what "they credit" for the success of the 6.5 Creedmoor is basically advertising hype. It's selling like hotcakes, because they've been sold as mighty tasty, but it's JUST another cartridge, better by only the slimmest of margins, if at all.

Back when Ackley was having his day in the sun, guys like Art Mashburn and Fred Huntington were using shoulder angles from 28 to 40 degrees. They all had their versions of "improved" cartridges, where case taper was removed and shoulder angled steepened. Mashburn thought 30 degrees was best for everything, so that's what all of his cartridges had. Huntington made several popular rounds with a 28-degree shoulder, at least a couple of which were replaced by factory offerings. Later, Palmisano and Pindell came along and made short-fat rounds in 22 and 6mm, both with 30-degree shoulders, that set the bench rest world on fire. Their cartridges had much less case taper than the 7.62x39, although the 220 Russian had already solved much of that "problem".

Point being - shoulder angle isn't the whole story, when it comes to applying AI principles to a cartridge.
 

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The Hog Whisperer (Administrator)
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They credit the Creed's accuracy to its 30°(or is it 35°) shoulder. Supposed to give a more consistent burn when packed in the short-fat cases. Like the 6.5 Creed is supposed to match speed with the .260, but do it with less powder.....more efficient.
Nobody has ever offered scientific 'proof' of one shoulder angle making any difference whatsoever. Just opinions.
 

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Elk Whisperer (Super Moderator)
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Mostly Ackley did it to add to the case volume.

If you put the same powder by weight in an IMP. case that is a maximum load for a standard case and fire it in your IMP. rifle, you get a lower velocity.

RJ
 

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Nobody has ever offered scientific 'proof' of one shoulder angle making any difference whatsoever. Just opinions.
Indeed. Some of those opinions are aggressively defended in forums because they were flaboyantly evangelised by gun writers as accepted dogma. Repetition made some readers accept the poorly explained theories as settled science.

The moment the bullet is being engraved by the rifling the geometric size and shape of the case has no bearing or influence whatsoever on its internal or external or terminal ballistics. Outside the barrel there are mere metres in distance between co-existence of flight paths between all calibres from the 6mm Rem to the .416 Rigby. Even the old .303 Brit with a heavy 174gr bullet has only 1/2 MOA difference with a 175 gr 7mm Rem Magnum 175 gr bullet at 250 metres if both are zeroed at the standard 200 metres.
 

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Seem's to me I read somewhere long ago that Ackley's favorite was the 250 Imp. what I read was he though the rest of the improved lot never lived up to his expectation's. Seem's he felt that only the 250 gained enough by improving to make it worth while. I think what Ackley was actually looking for was efficiency and increase in velocity was simply a by product. For me, I wouldn't waste my time turning any cartridge into an Ackley Imp. If you really need more than a 280 can give you, maybe you should look at a 300 mag!
 

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Discussion Starter #11
Seem's to me I read somewhere long ago that Ackley's favorite was the 250 Imp. what I read was he though the rest of the improved lot never lived up to his expectation's. Seem's he felt that only the 250 gained enough by improving to make it worth while. I think what Ackley was actually looking for was efficiency and increase in velocity was simply a by product. For me, I wouldn't waste my time turning any cartridge into an Ackley Imp. If you really need more than a 280 can give you, maybe you should look at a 300 mag!
What are you talking about? I do have a 300 mag lol
 

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my own take on doing the ai version is limited to one ai!!!:p

i bought a tc encore 27" MGM heavy factory barrel in 22-250 ai with a 40deg shoulder. i can't remember if it was 1 in 7" or 1 in 9" twist, could be a 1 in 8":(. anyway i loaded 22-250 60gr bullet with varget to fire form them. then the next step was a fl ai, then wet tumble, then i trimmed them to all the same length. then its time to reload.


pro:
i did 250 cases, 7 - 9x reloads and i didn't need to trim them again after the 1st firing. i sold the barrel, dies and casing, but i'm pretty sure that they would go 15-17x before trimming.

accuracy was unreal!!! a 1/2" at 100 yards(5 - 10 shots/benched) would be most likely. i used varget, imr 4831, imr4350 and h4831sc, also i use 60ish gr and 80ish gr bullets(bthp, hornady and nosler most of the time). a 1/4" group does not put a smile on my face. 1/8" group then i have a smile!!!

the barrel life of my 22-250ai was good(1700-2200 firings).


con:
the speed of the bullet is around 50-75fps faster than a 22-250. its nowhere near the speed that i imaged(150fps+ faster). and i loaded them hot. also i know that some cartridges do around 100-150fps faster.

reloading was expensive(its more than $40), i paid around $80 to get redding dies. but i paid ch4d 35-30 dies a $115, hornady 500 linebaugh about $80, redding 20 vartarg was around $75 too. while expensive, you only pay once. besides, i've watched dies that go new around $150-250!!!!





now having said that, in all my knowledge:eek:, i would buy another one. i happen to have a 93 spanish mauser that need rebarreled to a 7x57ai. i'm thinking about it, but thats for a later date.

in case you are wondering why? i hate trimming!!!!!!!!!!!
 

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The Shadow (Super Mod)
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If you gave the .264 WM a 30 degree shoulder, would it also improve speed, and efficiency?

Wouldn't a .260 AI be better than the CM ? If all other things are equal, excusing the long throat of the Creed.
They problem is people confuse "more speed" and "efficiency" all the time.
Efficiency is doing the same total work, with less, not more.

Blowing out the shoulders and increasing neck angle adds capacity, that's not equal work with less powder.

So taking an already bigger 260 case, and blowing it out when more to compare to the smaller capacity Creed; "all things being equal"?? Uhhhh.....:confused:

Grain for grain, doing more work work less is more efficient. The Creedmoor case is more efficient than the 260.
Is it a lot? No.
Does it matter? That depends, does it?
 

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Discussion Starter #14 (Edited)
If you gave the .264 WM a 30 degree shoulder, would it also improve speed, and efficiency?

Wouldn't a .260 AI be better than the CM ? If all other things are equal, excusing the long throat of the Creed.
They problem is people confuse "more speed" and "efficiency" all the time.
Efficiency is doing the same total work, with less
I hope you arent replying to me. If so, you misunderstood me. Because we are speaking to efcientcy the same way. A .30 TC out-performs a .308 Winchester with less powder. That is what I call efficient. 6.5 CM vs .260 is the same argument. The Creed is more efficient than the .260, but it is NOT the be all, end all of all cartridges.

My actual question here Darky, is, would the .264 Win Mag, if "improved", use less powder to make its fast #'s?
 

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I don't believe you would achieve your goal. If the improvingresults in a larger case capacity, you'll have the same amount of powder in a bigger area and that equates to less pressure which equates to lower velocity.

With that said, since the 264 Win Mag headspaces on the belt you may be able to keep all else equal, put a 30 degree shoulder on it that keeps capacity the same, and take some velocity readings and see what you get.

Headspacing on the belt, after the first firing as long as you don't set the shoulder back and blow it back out upon firing you shouldn't see any stretch.

The only change in case length I see with my 35 Whelen AI is after sizing, and it's a couple thousandths longer at most. A quick touch-up with the trimmer seems to square the case mouth more than anything which accounts for the few thousandths. Fired cases measure the same as when they were loaded.
 

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The Hog Whisperer (Administrator)
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I hope you arent replying to me. If so, you misunderstood me. Because we are speaking to efcientcy the same way. A .30 TC out-performs a .308 Winchester with less powder. That is what I call efficient. 6.5 CM vs .260 is the same argument. The Creed is more efficient than the .260, but it is NOT the be all, end all of all cartridges.

My actual question here Darky, is, would the .264 Win Mag, if "improved", use less powder to make its fast #'s?
The 'Creed' is not "more efficient." It just runs at a higher pressure. Simple physics..... there is no such thing as a free lunch.....
 

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...would the .264 Win Mag, if "improved", use less powder to make its fast #'s?
There are shorter versions of a 6.5, based on a 300 H&H parent. Those shorter cases use quite a bit less powder to make almost the exact same velocity. The case doesn't need an AI treatment because it already has a reasonable amount of body taper and a reasonably sharp shoulder.

I hate to put it like this, but you seem to think some cartridges are magical and others are evil, attributing mystical qualities at both ends of the spectrum. Metallic cartridges store components and work to seal a chamber during the firing sequence. Their relative capacities, shapes, and operating pressures make little difference, really; they all have a great deal more in common than they have differences with which to distinguish one from another.

There are dozens of "6.5's", from diminutive to the absurdly over-bore. The 6.5 TC/U and 26 Nosler come to mind. Almost as a rule, the smaller a case is, the more efficient it is; the velocity they produce, per grain of powder consumed, is almost always higher. However, the larger case will ultimately be capable of higher velocity, if you're willing to sacrifice "efficiency" and barrel life.

It's funny that you hate on the 6.5 Creedmoor so much, because it is probably the most efficient cartridge to shoot .264" diameter bullets that has ever been devised. It can be argued that it's the best blend of capacity and performance, all things considered. Several other cartridges are very close in that argument, one of them almost as old as smokeless powder, itself (the 6.5x57).

They're all just cartridges, Tang; no magic, no mystery. Pick one you like and shoot it. Shoot enough different ones, including some that are obsolete, or wildcats, or just really obscure, and it will gradually become more and more apparent to you...that they are all just cartridges. There are several hundred common ones and thousands of derivations, but very little to distinguish one from another. This is especially true when considering the small to medium bore offerings from the last 120 years, or so. During that time frame, a whole pile of cartridges have been developed, but there's so little difference between them that it doesn't make a whole lot of sense to deliberate over them.

I know, because I've spent quite a bit of my adult life doing so. ;)
 

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The 'Creed' is not "more efficient." It just runs at a higher pressure. Simple physics..... there is no such thing as a free lunch.....
Like Mike says they get better numbers from cartridges by increasing the pressure limit, doing that safely is achieved by increasing the strength of the case and making sure that all the guns manufactured for the new cartridge can handle the pressure, that usually means only bolt guns or AR's.
I believe sharp shoulders and minimum body tapers are great for the reloader, stops excessive case stretching and makes it easier to size the case the correct amount.

I would add that the Creedmoor specs call for the rifle chambers to have long throats and most have barrels with faster twists for longer bullets, unlike the 260 those long bullets don't protrude down into the case taking up case capacity, consequently the full case capacity can be taken advantage of, that could easily be described as "more efficient".
 

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Discussion Starter #19 (Edited)
I hope you arent replying to me. If so, you misunderstood me. Because we are speaking to efcientcy the same way. A .30 TC out-performs a .308 Winchester with less powder. That is what I call efficient. 6.5 CM vs .260 is the same argument. The Creed is more efficient than the .260, but it is NOT the be all, end all of all cartridges.

My actual question here Darky, is, would the .264 Win Mag, if "improved", use less powder to make its fast #'s?
The 'Creed' is not "more efficient." It just runs at a higher pressure. Simple physics..... there is no such thing as a free lunch.....
Toe-may-toe, ta-motto.

Higher pressure, allows same speed with less powder. That is "more efficient" no matter how you try to slice it. A car with 400 hp can get better gas mileage than one with 3
200 hp if they are driven correctly. In that scenario you wouldn't hesitate to say it's more efficient, would you?

Mikey-G said:
there is no such thing as a free lunch.....
Bovine Poo! Go to Burger King, order a combo. Eat all your fries, and all but 3 bites of your burger. Stick one of your wife's hairs in it. Go to the counter, tell them you almost puked. You will get your money back. Done, free lunch
 

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The Hog Whisperer (Administrator)
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Then the 'efficiency' of any cartridge, can be changed by merely adjusting the maximum pressure it operates at, right?
 
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