Brass and caliber

[chetc]

looking into building a 6.5 something, been hearing the 6.5x47 has an edge in accuracy over the creedmoor and the .260, if so, as far as brass of the 3 calibers which is more commonly available. also been thinking of the 6 Dasher, going to be using the rifle for out past 5-600yds

Chet

[psharon97]

Interesting question regarding availability. For average number of manufacturers, I would say it would be a wash between the 260 and the 6.5 creedmoor. For the 260, Remington, Lapua, Nosler and Norma make brass. For the 6.5 creedmoor, Norma, Nosler, and Hornady all make brass. For the 6.5x47, Lapua, to my knowledge, is the only manufacturer that makes that caliber.

However, the 260 has an edge over the 6.5creed and the 6.5x47: one can easily neck up or neck down any 308 based cartridge to make 260.

As far as which one is more inherently accurate: I don't have enough data between those three to say. I do own a 260, and it is boringly accurate. It doesn't care about the seating depth, velocity, or powder that I've tried. The 2 bullets I've tried are the 140gr berger hybrid and the 140gr Hornday soft nosed bullet. The difference in group size at 100 yards is hard for me to distinguish.

If you want a DBM system and be able to seat the bullets out as far as possible, get the 6.5x47. The 6.5creed will be about in the middle with overall length, with 260 being the longest of the three, all things being equal.

[scope eye]

MOST shooters are not proficient enough to be able to tell the difference between those three different chamberings, so I would not let that be a factor in choosing it, with everything factored in the Creedmoore and 260 Rem are your best choices.

Dean

[darkker]

Yeah, hook-up your pressure trace and the 260/Creed are identical. The x47 is somewhat slower, but arguably not enough to matter.
The talk of the 47 being more accurate, is typically based around the small primer pocket, and small flash holes. Those attributes CAN make it more accurate, but the operative word is can. If that type of thing gets you excited, then wait a few months. Lapua is building Creedmoor brass with the same small pockets/flash holes.

[Robinhood]

6mm creedmoor.

[SavRimfire]

For the most part, no one cartridge is any more or less "accurate" than the other. Some may certainly be easier to find their sweet spot accuracy node and this is often the case with cartridges that are less overbore, but just because one is easier to find that node doesn't make it more or less accurate than the next.

[sharpshooter]

Years of evolution in the bench rest game would prove otherwise.......:(

[SavRimfire]

Years of evolution in the bench rest game would prove otherwise.......:(

If this were actually true, they'd ALL be shooting the EXACT same cartridge.

[foxx]

If this were actually true, they'd ALL be shooting the EXACT same cartridge.

So how much variety are you seeing out there among the top 20% of shooters? Is any one winning with 30-06 Rem or .308 Win or .270 win or .444 Marlin or 45-70 Govt?

[SavRimfire]

So how much variety are you seeing out there among the top 20% of shooters? Is any one winning with 30-06 Rem or .308 Win or .270 win or .444 Marlin or 45-70 Govt?

No you don't but the reason you don't isn't because any of those are less accurate than another. Some of the big 30's such as the 300Wby, 300Win mag. used to rule the 1000 yard BR world. Then it was .284/7mm stuff and now it's largely .265/6.5mm & .243/6mm but it's not because they're more accurate than any of the big 30's that used to rule the BR world.

To often, people think just because THEY can make a certain cartridge shoot better than another, it's because the one they can make shoot better is more accurate.

Something to consider, if the brass quality for particular cartridge is much better and more consistent from piece to piece, than it is for another, it will very possibly allow the one with much more consistent brass quality to out shoot the one with lesser quality brass due to the inconsistencies or variances in the brass. BUT, that doesn't mean one is anymore accurate than the other by design, it's just that one has better components.

The notion one is more "accurate" than another is about as comical as the notion a bullet rises in an arch, on its own, once it leaves the barrel on its way to the target.

[foxx]

Hmm... So the physical properties and characteristics of the 6.5 or 6mm bullet has nothing to offer a target shooter over a .308 or .204 caliber bullet? One is not better in the wind, for example? Every caliber has the potential for developing a bullet that is as good as the next for long range shooting? What does "Bullet Coefficient" have to do with all of this? Just a bunch of nonsense, I suppose.

[SavRimfire]

Just a bunch of nonsense, I suppose.

Not saying that at all but you are talking about components, not cartridge design.

[foxx]

No, I am saying there are cartridges that are inherently more accurate for shooting at specific ranges than others. For example, the 6 PPC is better than the .308 at 100 or 200 yards. Likewise, the .260 or .243 is more accurate at longer ranges. .308 has its advantages over all of these, but inherent accuracy equal to these is not one of them.

And I AM talking about cartridge design. I am comparing different CARTRIDGES. I was also asking if you were saying all cartridges are capable of shooting bullets of the ideal BC for any given situation?

Whatever.

[Robinhood]

I call B.S. I understand what you are saying but components are what the cartridges are made of. All things being of equal quality, a 6.5 will dominate a 30 cal to 1500 yards. I tried and tried to get a 308 to shoot expert at 1000. it was taking to much time and money. enter the 260 and the first time out I shot an expert score. Now if you are talking 100 yards in a vacuum tube, that's a different story.

[darkker]

. Likewise, the .260 or .243 is more accurate at longer ranges.

You just whiffed with this one Foxx.
I understand everyone has a different notion about how to "better" accomplish any given task, but what the 243 is known for isn't this. What it is known for by every Ballistics lab there is, is random unexplainable pressure excursions particularly when shooting heavy bullets with appropriately slow powders. Random "Ruh-Roh, Raggy" moments do not describe an inherently accurate cartridge design.

Does it shoot very sexy BC bullets quickly? Yes. Can it turn in some very impressive groups at distance? Certainly! Does that mean it's because the cartridge design is inherently accurate? No.

[psharon97]

looking into building a 6.5 something, been hearing the 6.5x47 has an edge in accuracy over the creedmoor and the .260, if so, as far as brass of the 3 calibers which is more commonly available. also been thinking of the 6 Dasher, going to be using the rifle for out past 5-600yds

Chet

The reason why so many of the top shooters, IMO, use the 6mm or the 6.5mm is the law of diminishing returns. In order to get a 30cal bullet to perform at the same levels as the 6 or 6.5mm bullet, the 30cal will have to be driven at much higher velocities, the bullet will have to weigh substantially more, barrel life will suffer dramatically from being so overbore, and recoil will be higher. Whereas a 6 or 6.5 can perform at comparable levels with less powder, less recoil, and better barrel life. Simply put, economically speaking, it's far cheaper to get a 260 remington to perform at comparable levels as a 300 winmag. Top shooters realize this, and switch to a 6 or 6.5 to help eliminate the weaknesses associated with 30cal bullets.

If your goal is inside of 1000 yards, then almost any of the popular long range round for 6mm or 6.5mm will do the job admirably well. If you don't reload, I would look at something like a 243, or a 6.5 creedmoor. If you do, then the sky is the limit. Sharpshooter is correct, the 6.5x47 will have the longest brass life and barrel life, provided you don't push the pressures to the max every time. The 6.5x47 will not develop the pressures necessary to propel a 140gr bullet at the same velocities as a 260. However at 600 yards the velocity gains between the 260, 6.5 creedmoor, and the 6.5x47 will be negligible in field conditions. Learn to read the wind, the conditions, and start shooting. Don't be concerned so much with the best caliber possible.

[foxx]

You just whiffed with this one Foxx.
I understand everyone has a different notion about how to "better" accomplish any given task, but what the 243 is known for isn't this. What it is known for by every Ballistics lab there is, is random unexplainable pressure excursions particularly when shooting heavy bullets with appropriately slow powders. Random "Ruh-Roh, Raggy" moments do not describe an inherently accurate cartridge design.

Does it shoot very sexy BC bullets quickly? Yes. Can it turn in some very impressive groups at distance? Certainly! Does that mean it's because the cartridge design is inherently accurate? No.

WTF are you talking about, Darkker? I "whiffed"? My point is NOT whether the .243 is the best cartridge at long distance. My point is the accepted wisdom of the shooting community is that there are cartridges better (or worse) suited for accuracy at different ranges. SavRimfire seems to be asserting, rather authoritatively, the exact opposite. He seems to be saying, that any cartridge can be made just as accurate as another. I don't believe that, and it's a rather unconventional opinion that actually defies my sensibiltities. I am trying to understand what his point is. If the .243 is not all that accurate, as I suggested above, Darkker, than your assertion only serves to support mine. Different cartridges have different inherent accuracy potential.

[scope eye]

Come on guys lets keep it civil, I was enjoying this thread up to a point.


Dean

[darkker]

Let's keep this clear.
I didn't throw my hat into the "my cartridge is more efficient, than your cartridge" debate; merely correcting an incorrect statement.

His assertion is that any cartridge is as naturally accurate as another, as is evidenced by results. Perfectly reasonable point of view.

Your assertion is that their are natural cartridge efficiency differences. Based on what you said in post #13 and I partially quoted you on, that natural difference is evident in the 243 & 260 at long range.
In fact that difference isn't evident by your example. Your example is evidence of a result, not an inherent nature of a cartridge design; exactly as I said.

Call any Ballistics lab and ask about the random pressure excursions, the 243 and 7mm RM are the two worst offenders. That is repeatable, scientifically measurable, peer reviewed, fact. A cartridge that runs away on its own is not inherently accurate, as you claim it to be. It would be inherently unpredictable.

Now you can see this however you want to.
A. Because your example was wrong, and only proves a wild cartridge can in fact be used competitively with great success; that actually goes to the other side of the argument. That in fact any cartridge can be accurate, despite claims of natural voodoo.
B. There are naturally inherently accurate cartridges. But as your example shows, in fact the knowledge of the shooting community when it comes to cartridges, is rather pathetic in terms of design.
C. Something else.

Remember how many people are constantly repeating claims of watching "for pressure signs", and they don't mean watching the chronograph. How many are proud to claim velocities that are blatantly over-pressure, and are happy to share the load? How many give load data in grains as though there were no such thing as lot variations? Or better yet, how many people do all that while buying powder from a company who won't even tell you directly what their nominal lot variances tolerance is?!!

Don't lean to heavily on the "accepted wisdom of the shooting community". A man can be perfectly smart and reasonable. A group of them can easily be dumb, superstitious animals.

[yobuck]

1000 yd competition has (evolved) over time to develop to where it is today.
Good shooters with accurate guns that work well in getting 10 shots downrange in well under 60 seconds are now dominating.
The smaller less recoiling cartridges like the 6mm dasher are helping to make all that possible.
Change the rules so as to eliminate that type rapid shooting, and the caliber selection would no doubt change.
The world record 1000 yd group for heavy gun class is still held by a 30 cal.
So in reality, what works best, is best for a particular situation. But not necessarily for every relay even during the same match.
Winners have good equiptment and know how to shoot in order to win. And other good shooters don't.