264 Win Mag VS 270 Whby

[lloydsmale]

so your saying that the 3006 has 50percent more barrel life then a 308 and is more accurate??? Barrel life has alot more to do with the pressures you run a round at and what powders your using to get it there by far then it does with the design of the case. This isnt my first rodeo. Ive been shooting and loading for 40 years. When i post its a opinion based on what actually was seen by me. I will look at internet opinions and yes ive gained knowlege from them. But i surely factor in that i have no control over the exact conditions someone else used. Id bet about half the storys about guys burning out barrels are just a weak attempt to sound like there real shooters or trying to convince someone they know what there talking about. I know theres a few guys here that are real shooters. Guys that do actually wear out barrels but id also bet that 75 percent of guys claiming it are just full of bs. They start quoting math and theroys they gotten from someone else.

where have you been for the last four or five years??? There's been a constant gripe about the 800 round barrel life. The one savings grace for the round is the 35 degree shoulder angle. Had the neck been about .32" in length, it'd would have had a much longer barrel life. Long necks and sharp shoulders put together are well known for long barrel lives and better groups. A really good example is the compairison between the 6.5/.284 and the
6.5-06AI. One has a 35 degree shoulder and the other a 40 degree shoulder One has a .264" neck length and the other is about .32" in length. Case volume is similar between the two. But one will have at least a 50% longer barrel life alone (usually more than that). You can do the samething with the .308 Winchester as compaired to the generic 30-06, or the .243 to the 6mm
gary

 

[Long Time Long Ranger]

I shoot both the 264 winchester and the 270 wby. Both do the same thing basically and serve the same purpose. I have not tried the new specialty bullets in the 270 wby but some like the matrix give it an advantage at long range on game. I love shooting both of them. I just tried the 130 grain cutting edge bullet in my 264 winchester which is a specialty high bc bullet per weight. It shot extreme accuracy at around 3400 fps which gives it some really nice ballistics. The 264 winchester is the 7mm remington necked to 264 so anything said about it can be directly applied to the 7mm remington. The old barrel life myth about the 264 winchester is just that, a myth. My 264 STW has way better ballistics than either of these and a good long range choice. However barrel life issues can come into play there with probably less than 1000 rounds with top accuracy. That is just a guess. Mine has a few hundred shots and still shoots .25 moa.

 

[Trickymissfit]

so your saying that the 3006 has 50percent more barrel life then a 308 and is more accurate??? Barrel life has alot more to do with the pressures you run a round at and what powders your using to get it there by far then it does with the design of the case. This isnt my first rodeo. Ive been shooting and loading for 40 years. When i post its a opinion based on what actually was seen by me. I will look at internet opinions and yes ive gained knowlege from them. But i surely factor in that i have no control over the exact conditions someone else used. Id bet about half the storys about guys burning out barrels are just a weak attempt to sound like there real shooters or trying to convince someone they know what there talking about. I know theres a few guys here that are real shooters. Guys that do actually wear out barrels but id also bet that 75 percent of guys claiming it are just full of bs. They start quoting math and theroys they gotten from someone else.

as old Bill Calfee once said, the best way to shoot great groups starts with a great barrel. Ferris Pendell and a few others have said exactly the samething. Now barrel life and throat errsion has a lot more to do with case design than much of anything else. Parker Ackley expounded on this a lot during his lifetime, and the cause has been taken up several times in Precision Shooting and a few other places. If the votex of the flame path enters the throat area, you will have a short barrel life. This isn't some "internet idea", but from folks a lot smarter than us and has been proven out almost daily.

Ackley states in his book (page 165 thru 175 Vol. II) that an overbore cartridge pushes unburnt powder down the barrel, and literally eats the inside of the bore with grains of powder. It was either Bob Greanleaf or M.L. McPherson that wrote about these same issues thirty years later in P.S., and there was nobody arguing with him about it. As I said the essay about the Turbulance Point should be a must read. You get into your CAD program, and make a drawing of the case, and extend the shoulder angles to where they cross. That's the T.P., and also the hottest part of the powder burn. If it ends up in the throat, you shorten the barrel life. You add this into the equation, and you get a very short barrel life. The idea is to have the hottest point of the burn in the first 2/3rds or 3/4 of the neck, not in the throat
gary

 

[backwoods83]

I'm going to go with Gary on this one, indeed a 30-06 will last just as long as a 308, the 30-06 will fire crack 6-8" down the barrel, the 308 will erode the throat, 6 of one, half dozen of the other.

 

[Nomosendero]

I'm going to go with Gary on this one, indeed a 30-06 will last just as long as a 308, the 30-06 will fire crack 6-8" down the barrel, the 308 will erode the throat, 6 of one, half dozen of the other.

Hmmm, interesting!! I have heard far more about long barrel life with the 308 than the '06, partly because far more volume shooters shoot the 308. I think I would run with that evidence for now, just me.

 

[backwoods83]

When I sitting at the range I can put 50 rounds through either in under an hour and neither one heats. Both will go as far as 10k rounds with a good barrel.

 

[112Savage]

we are slightly detracting from the OP's decision to be made, but coincidentally there is a similar threat propagating on Accurateshooter.com talking about neck length and erosion. Using similar math to that used in the following article and high school trigonometry classes.
Is there magic in a case's shoulder angle relative to its neck length? @ www.reloadersnest.com

The 264 WM has a turbulence point 109% the length of the neck which is significantly less than the 223 remington 130%, 308 winchester 139%, 30-06 springfield 129% or the 300 winchester magnum 125%. Personally having owned a 223, 25-06, 264wm, and 308 throat erosion may be slightly determined by the turbulence point but more so by the heat/pressure and dwell time of that heat and pressure.

I think its bull hockey to believe that tangental abrasion of the throat by burning powder is the primary factor to blame for worn out lands.

 

[apexmtnman]

I think I'll just let you guys worry about turbulence point, shoulder angle, length of neck and so on, I'll just take my poorly designed, long in the tooth old 264 Win Mag and shoot the heck out of it. If it shoots out a barrel so what, I've got a new Kreiger sittin in the safe to replace it, haven't had to yet.
Trickymisfit I do know the 6.5x284 has a reputation of being hard on barrels (I read it on the internet) but sure seems like quite a few guys are still shooting them in competition anyway, I was just making mention that the short neck doesn't seem to have a big effect on accuracy in its case.

Match Results

There's 3 guy's shooting 300 Win Mags, one guy shooting a 300 Roy, but I don't see anyone shooting a 264 or 270 Roy.

 

[lloydsmale]

luckily my guns arent super smart and have attened math and science classes and dont have access to the internet. I guess there just ignorant enough not to know there suppose to be wearing out so soon.

 

[Trickymissfit]

Hmmm, interesting!! I have heard far more about long barrel life with the 308 than the '06, partly because far more volume shooters shoot the 308. I think I would run with that evidence for now, just me.

How do you say this, and keep it simple?

The shoulder angle acts like a funnel directing the hot gases into a flame path moving towards the throat and onwards. Where the two shoulders would meet in an imaginary angle is known to be the hottest point. The narrower the angle the further the vortex is projected out from the shoulders into the neck. Ideally we want this place to be in the first two thirds of the neck, or maybe even less. Now to get back to the .284 case a sec. The 35 degree shoulder angle is good, but the short neck length takes most of that advantage away. On the otherhand the 6.5-06 is just as bad with it's way too acute shoulder angle, but it does have a much longer neck length (about .32"). This is why a 6.5-06 imroved (there are several) has such a good barrel life. It's not really a knock on either case type, but it's to point "this is what you get." I personally like the 6.5x55 AI case design using a 6.5x57 as a parent case to make up for the known case shrinkage during fire forming (will be close to .04"). If you don't shoot but a hundred rounds a year, you'll never worry much about the issue. Yet if your a "F-Class" shooter you will.

The 6.5-06 is a little bit overbore as is the 6.5-.284. Not a tremendous amount, but still overbore. The 57mm case is not. Kinda reminds me of three guys I know that shot the 6-.284 in long range varmit rigs. They all used high end barrel blanks, but still changed barrels often. One of them gets the idea that he's going to mod the .284 case by pushing the shoulder back .100" with the rest going into the neck. He looses about 50fps, but is able to use the same barrel for well over twice the rounds. His buddy likes his idea and does one .150" short, but trims the necks back to about .33" (the other guy used the same neck length as a 6mm remington). He looses about 75 to 80fps compaired to the 6-284, but his groups are better. He gets almost two years out of the barrel! One of these guys sent me a pic of a marmet he shot at 800 yards using the Berger 88LD bullet. Had a grin on his face big enough to stuff a soft ball in it!!
gary

 

[Trickymissfit]

I think I'll just let you guys worry about turbulence point, shoulder angle, length of neck and so on, I'll just take my poorly designed, long in the tooth old 264 Win Mag and shoot the heck out of it. If it shoots out a barrel so what, I've got a new Kreiger sittin in the safe to replace it, haven't had to yet.
Trickymisfit I do know the 6.5x284 has a reputation of being hard on barrels (I read it on the internet) but sure seems like quite a few guys are still shooting them in competition anyway, I was just making mention that the short neck doesn't seem to have a big effect on accuracy in its case.

Match Results

There's 3 guy's shooting 300 Win Mags, one guy shooting a 300 Roy, but I don't see anyone shooting a 264 or 270 Roy.

here's my take on the 6.5-284 and also the 6.5-06: If you shoot slowly and try and keep the barrel as cool as you can; you will be OK. Yet if your shooting a round every 20 seconds you will be buying a new barrel. An improved 6.5-06 will most deffinitly be better that the other two.

The main reason nobody is shooting the .270 mag in 1000 yard shooting is lack of target grade bullets for starters. The 6.5's came into vogue due to recoil alone. Others have tried 6mm bullets and others have even tried 22 centerfire stuff.
gary

 

[Long Time Long Ranger]

Exactly, the lack of good bullets in 270 is what has hurt it through the years. Most every 270 caliber factory rifle is a 1-10 twist limiting bullet makers from offering high bc bullets for it. With some of the specialty bullets and custom barrel twists the 270 will hold it's own with anything. But why would anyone want to go to the expense of all that when better offerings are available in similar calibers cheap. Down to 264 and up to 7mm and there are many cheap high bc bullets. That is what has limited the 270.

Having shot both the 270 wby and 264 winchester for years the barrel wear issue is mute in a hunting rifle. Unless you are a competition match shooter the barrel wear issue is irrelavent. In a hunting rifle you will not notice barrel wear difference between the 284 case and '06 case. The 6.5-06 AI is faster with the larger case capacity but arguing barrel wear is mute between the two unless you are a competittion shooter pushing thousands of rounds quickly through a barrel. As a hunting rifle not an issue. I shoot the 264 winchester and 264 STW regularly and even with those as a hunting rifle barrel wear is not an issue. If those are not an issue then arguing the '06 and 284 case is mute.

 

[apexmtnman]

How do you say this, and keep it simple?

The shoulder angle acts like a funnel directing the hot gases into a flame path moving towards the throat and onwards. Where the two shoulders would meet in an imaginary angle is known to be the hottest point. The narrower the angle the further the vortex is projected out from the shoulders into the neck. Ideally we want this place to be in the first two thirds of the neck, or maybe even less. Now to get back to the .284 case a sec. The 35 degree shoulder angle is good, but the short neck length takes most of that advantage away. On the otherhand the 6.5-06 is just as bad with it's way too acute shoulder angle, but it does have a much longer neck length (about .32"). This is why a 6.5-06 imroved (there are several) has such a good barrel life. It's not really a knock on either case type, but it's to point "this is what you get." I personally like the 6.5x55 AI case design using a 6.5x57 as a parent case to make up for the known case shrinkage during fire forming (will be close to .04"). If you don't shoot but a hundred rounds a year, you'll never worry much about the issue. Yet if your a "F-Class" shooter you will.

The 6.5-06 is a little bit overbore as is the 6.5-.284. Not a tremendous amount, but still overbore. The 57mm case is not. Kinda reminds me of three guys I know that shot the 6-.284 in long range varmit rigs. They all used high end barrel blanks, but still changed barrels often. One of them gets the idea that he's going to mod the .284 case by pushing the shoulder back .100" with the rest going into the neck. He looses about 50fps, but is able to use the same barrel for well over twice the rounds. His buddy likes his idea and does one .150" short, but trims the necks back to about .33" (the other guy used the same neck length as a 6mm remington). He looses about 75 to 80fps compaired to the 6-284, but his groups are better. He gets almost two years out of the barrel! One of these guys sent me a pic of a marmet he shot at 800 yards using the Berger 88LD bullet. Had a grin on his face big enough to stuff a soft ball in it!!
gary

Speedy Gonzales has another theory on the subject.

THROAT SANDBLASTING THEORY

"The amount of powder and heat generated is the culprit to early throat erosion."

 

[Trickymissfit]

Speedy Gonzales has another theory on the subject.

THROAT SANDBLASTING THEORY

"The amount of powder and heat generated is the culprit to early throat erosion."

1. the actual case in the chamber becomes a pnematic gas cylinder when the charge is ignited. Speedy is right, but also slightly wrong by using the laws of fluid dynamics in his thoughts. They work slightly different.

2. upon ignition and during the powder burn the inside of the case comes under pressure (extreme), and kind of mimics an accumulator used in a hydraulic circut (note: there are pneumatic accumulators, but not commonly used). Any piece of solid matter will move about inside the case (Ackley points this out in that chapter I spoke). Now all this is going on in milli seconds, and this is also a reason that fluid dynamics cannot apply (speed of the reaction is the issue). On the otherhand a pneumatic circut is much more reactive to pressure changes in speed and volume.

3. Now taking the above two paragraghs and putting that together with Speedy's comments. In the world of physics and applied mechanics (we are combining both here), it is a law in physics and applied mechanics that a vector of energy will always seek the path of least resistance. The unburnt granuals of powder simply does not keep bounching around in the case. It's drawn into the barrel right behind the bullet. Why? Because the given size of the cylinder (in this case the cartridge case) is growing in volume as the bullet travels down the barrel. While this is happening the actually pressure and velocity of the gas charge is also reducing itself in an inverse proportional square. That's one reason why the throat goes long before the barrel does.

good post by the way
gary