What exactly is "inherent" accuracy in regards to a cartridge?

[jerkface11]

Or because 6mm ppc can shoot a bullet with a better ballistic coefficient. But we can go with magic if you guys insist

 

[cmb3366]

If accuracy is about ballistic coefficient and bucking the wind, why is short range benchrest shot exclusively with short, flat based bullets?

Look at proven match winners, like the 6mm 68gr launched from the PPC with a bc of ~0.280, or the .308 115gr launched from the BR with a bc of ~0.290, and it becomes obvious that shooting world-class groups at ranges under 300yds is not a result of high ballistic coefficient, but consistency in bullet jacket dimensions, bullet base dimensions, and a smooth and exceptionally consistent powder burn to launch said projectile.

 

[tipoc]

Or because 6mm ppc can shoot a bullet with a better ballistic coefficient. But we can go with magic if you guys insist

A better BC is one factor in designing a "inherently" more accurate round. As fellas have explained case design, primer, powders used, bullet design, etc. can make a round more clearly capable of repeatable accurate fire and precision. There is no reason for "magic" to be involved at all. Many have prayed their bullets fly true but it's usually the design and loading that make it so. There is more to it than just bc.

Both the 30/40 Krag and the 7x57mm Mauser round were developed for smokeless powder and chambered in different rifles, the Krag-Jorgenson for the U.S. and for the Spanish the 1893 Mauser rifle.

They met in Cuba where about 750 Spanish troops defended San Juan and Kettle hills against more than 6,500 Americans. The results are well known and the U.S. Army felt so strongly about it that they set out to copy both the Mauser rifle and the 7x57 Mauser round. They did which is how we got the Springfield rifle and eventually the 30-06.

Ditto the Boer War for the British. Against the 7x57 in South African hands the British redesigned both their rifle and ammo afterwards.

If we look at the design of the 30/40 Krag against the 7x57 Mauser rounds you can see that it's more than just the bc.

tipoc

 

[Nom de Forum]

Or because 6mm ppc can shoot a bullet with a better ballistic coefficient. But we can go with magic if you guys insist

The explanations for what factors make a cartridge inherently more accurate than another have been explained sufficiently in this thread for anyone of average intelligence and having a rational mind to understand and accept as factual. Stop embarrassing yourself with comments that indicate you are trolling.

 

[Nom de Forum]

Just going back to the bit about how any cartridge design can dominate a precision oriented sport, the 30-30 case did in fact dominate the short-range benchrest game for over a decade as the 219 Donaldson Wasp, it was the gold-standard that won matches every weekend. Then Merle Walker unleashed the 222 case on the sport and overnight shooters using the 222 in the same actions and barrels used by 219 shooters started winning. The fact of the matter is that the 222 groups more precisely over the long strings measured in benchrest than the 219, and shooters are correct to say that it is inherently more accurate.

At the present date, try shooting a short range match with a 222 built by the finest smith using turned lapua brass and your pet load. You will shoot impressively small groups, but you will be beat when looking at aggregates by the guys running the 6ppc and 30br. Simply put, a mountain of data shows that those two cartridges are capable of putting their bullets in tighter groups than the 222 over the long term, and as a result, they win matches.

All that said, I don't think to the average rifleman needs to be concerned with inherent accuracy. The average rifle, and more importantly, the average barrel just cannot show the difference that exists between cartridges.

Great post elaborating the progression in cartridge technology used for precision shooting. Some cartridges are just better at producing very uniform velocities from shot to shot. That slight advantage makes the difference between winning and losing if all other things are equal.

Edit: According to Cartridges of the World the .219 Donaldson Wasp is based on .219 Zipper case and the .219 Zipper is based on a modified 25-35 WCF case. The 25-35 WCF case has slightly different dimensions compared to the .30-30 WCF. It is interesting that the 25-35 case was chosen instead of the more prevalent ..30-30 case when the dimensions are so similar. Could it be something as simple as different case wall thickness at the point of shoulder and neck resizing?

 

[redneck2]

Or because 6mm ppc can shoot a bullet with a better ballistic coefficient. But we can go with magic if you guys insist

If he doesn't understand that the same bullet can be used in almost 6mm/.243/.244 rifle, then it's pretty much a lost cause.

I used to have a roommate like that. Stubborn as hell and always wrong. One day we were talking about the ocean and tides. I said something about high tide being when the moon had the strongest pull.

He just gave me the slack jaw look and said "what the "f" does the moon have to do with tides? Then went into a rant. I was trying to make him look stupid. I didn't have to try and he didn't need any help.

 

[Nom de Forum]

Both the 30/40 Krag and the 7x57mm Mauser round were developed for smokeless powder and chambered in different rifles, the Krag-Jorgenson for the U.S. and for the Spanish the 1893 Mauser rifle.

They met in Cuba where about 750 Spanish troops defended San Juan and Kettle hills against more than 6,500 Americans. The results are well known and the U.S. Army felt so strongly about it that they set out to copy both the Mauser rifle and the 7x57 Mauser round. They did which is how we got the Springfield rifle and eventually the 30-06.

tipoc

Regarding the performance of the Spanish in Cuba; the fact that many of the Americans were still equipped with black powder single shot .45-70s, the Spanish being in field fortifications on higher ground, and the faster reloading speed of the stripper clip magazine reloads of the Mausers compared to individual round magazine reloads of the Krag I think were even more significant factors. You are absolutely correct about the bullet design used in the Spanish rifles making a big impression but apparently not enough to prevent the U.S. from adopting the .30-03 cartridge with its 220 grain round nose bullet in the 1903 Springfield rifle three years before the adoption of the .30-06 with a 150 grain pointed bullet.

 

[tipoc]

Regarding the performance of the Spanish in Cuba; the fact that many of the Americans were still equipped with black powder single shot .45-70s, the Spanish being in field fortifications on higher ground, and the faster reloading speed of the stripper clip magazine reloads of the Mausers compared to individual round magazine reloads of the Krag I think were even more significant factors. You are absolutely correct about the bullet design used in the Spanish rifles making a big impression but apparently not enough to prevent the U.S. from adopting the .30-03 cartridge with its 220 grain round nose bullet in the 1903 Springfield rifle three years before the adoption of the .30-06 with a 150 grain pointed bullet.

The American Gatling Guns and the performance of the 10th Cavalry had a greater impact still and were likely decisive. Or at least the Gatling guns got more public credit than the 10th. The U.S. artillery which they brought was loaded with black powder and performed erratically.

The 30-03 was the first attempt to neck up the 7x57 for a 30 caliber round and was done directly in response to the experience in Cuba. The U.S. military was slow on the uptake (nothing new there) and were loath to dump what they had just adopted. But as I pointed out the 30-06 soon followed. But they stuck with a 30 caliber round for no really good reason other than that that's what they had been using and they had confidence in the caliber.

The performance of the round 7x57 and the rifle Mauser 93 made an impression.

Alexander Rose has a good bit on this in American Rifle.

tipoc

 

[Nom de Forum]

The 30-03 was the first attempt to neck up the 7x57 for a 30 caliber round and was done directly in response to the experience in Cuba.

tipoc

Your statement reads as if you are saying the .30-03 was a 7X57 case necked-up to .30 caliber. That is not true. Am I correct in assuming that you meant the .30-03 was the first attempt by the U.S. Army to create a .30 caliber cartridge that had the cartridge case design attributes of the 7x57?

 

[RetiredUSNChief]

A cartridge of any kind can only be "inherently accurate" within a prescribed set of circumstances. Outside of this, the term is meaningless.

Change any aspect of those circumstances and the cartridge in question cannot be said to be "inherently accurate" any longer.

The problem with describing a cartridge as "inherently accurate" is that there are two groups of circumstances which have to align themselves in order for this to be true:

- Circumstances describing the characteristics of the cartridge itself.

- Circumstances describing the characteristics of the firearm in which the cartridge is to be fired from.

The two must go hand in hand when describing the performance of the cartridge.

 

[george burns]

Thanks Chief

 

[natman]

Or because 6mm ppc can shoot a bullet with a better ballistic coefficient. But we can go with magic if you guys insist

It's not magic just because you refuse to understand it.

If it were *just* 6mm bullets then benchresters would be shooting all manner of 6 mm cartridges. But they aren't. For years the benchrest cartridge of choice was the 222 Rem. Then when the PPC cartridges came along the 222 became history.

The 222 was the choice because it was the most inherently accurate cartridge available at the time. When the PPC cartridges were developed benchresters went to them en masse because they were inherently more accurate than the 222.

Short powder column, sharp shoulder, case shape make a difference whether you want to believe it or not.

 

[Nom de Forum]

A cartridge of any kind can only be "inherently accurate" within a prescribed set of circumstances. Outside of this, the term is meaningless.

Change any aspect of those circumstances and the cartridge in question cannot be said to be "inherently accurate" any longer.

The problem with describing a cartridge as "inherently accurate" is that there are two groups of circumstances which have to align themselves in order for this to be true:

- Circumstances describing the characteristics of the cartridge itself.

- Circumstances describing the characteristics of the firearm in which the cartridge is to be fired from.

The two must go hand in hand when describing the performance of the cartridge.

Sorry Chief but I think you are missing the point. The label inherently accurate cartridge should mean the cartridge has, and more specifically the cartridge case, has intrinsic characteristics that make it possible to be more consistent shot to shot than a cartridge that does not have these characteristics. The firearm itself does not make the cartridge inherently accurate because it is just the means to demonstrate the inherent accuracy or lack of inherent accuracy of various different cartridges. Just like human beings, some cartridges have physical characteristics that from inception give them superior accuracy capability. I think much of the confusion and disagreement about the phrase “inherently accurate cartridge” is attributable to semantical differences.

 

[1911 guy]

Post #29 was the first (that I caught) and several others have stated the same:

"Inherent accuracy" is a function of a case designed with:
a short for diameter powder column for consistent burn rate,

case volume to allow for sufficient powder to attain full velocity potential without overpressure,

short overall length to minimize alignment errors either in chamber fit or bullet seating,

proper shoulder dimensioning to allow consistent headspace and chamber fit,

and last but not least, firing an aerodynamically sound bullet.

An excellent example is the .30-06 vs. .308 article linked in this thread. Compare the two cartridges against the list above. The .30-06 has more case capacity, but at the expense of every other item on the list. That's why the .308 gets the nod for accuracy work over the "-06.

 

[RetiredUSNChief]

Sorry Chief but I think you are missing the point. The label inherently accurate cartridge should mean the cartridge has, and more specifically the cartridge case, has intrinsic characteristics that make it possible to be more consistent shot to shot than a cartridge that does not have these characteristics. The firearm itself does not make the cartridge inherently accurate because it is just the means to demonstrate the inherent accuracy or lack of inherent accuracy of various different cartridges. Just like human beings, some cartridges have physical characteristics that from inception give them superior accuracy capability. I think much of the confusion and disagreement about the phrase “inherently accurate cartridge” is attributable to semantical differences.

OK.

Take your "inherently accurate cartridge" of choice and fire it from a smooth bore and see what it gets you.

Take your "inherently accurate cartridge" of choice and fire it from a barrel which isn't rifled for a twist rate appropriate for the bullet in your cartridge and see where it gets you.

 

[Nom de Forum]

OK.

Take your "inherently accurate cartridge" of choice and fire it from a smooth bore and see what it gets you.

Take your "inherently accurate cartridge" of choice and fire it from a barrel which isn't rifled for a twist rate appropriate for the bullet in your cartridge and see where it gets you.

That is just silly.

If you have two different cartridges, one of which has the physical characteristics of an inherently accurate design and the other does not, and you shoot each in a rifle optimized for it, one cartridge will be more accurate than the other. The more accurate cartridge will be the one that has case configuration characteristics that decades of research has determined creates inherently accurate cartridges. Are you having a hard time understanding this or are you just trolling me? Did you not read all the other posts from numerous people explaining what makes some cartridges inherently more accurate than others?

 

[RetiredUSNChief]

That is just silly.

If you have two different cartridges, one of which has the physical characteristics of an inherently accurate design and the other does not, and you shoot each in a rifle optimized for it, one cartridge will be more accurate than the other. The more accurate cartridge will be the one that has a case configuration that decades of research has determined creates inherently accurate cartridges. Are you having a hard time understanding this or are you just trolling me? Did you not read all the other posts from numerous people explaining what makes some cartridges inherently more accurate than others?

Actually...I'm having a great time reading up on the subject and trying to learn what this is all about, thank you very much.

And so far I'm not seeing a lot of justification anywhere that explains WHY a given cartridge is "inherently accurate". There's speculation...but nothing I can find that's actually technical, just more of a layman's comment as to "this is what makes it more accurate" here and there.

The cartridge at the top of the heap right now is indisputably the 6mm PPC USA, at least in the shorter ranges of benchrest shooting. Before that, it apparently was the .22 PPC, before that it was the .22 BR Remington, and before that it was .222 Remington. Feel free to correct me, but my point here is that there were other "top cartridges" before the 6mm PPC USA.


A cartridge is a combination of primer, brass, powder, and bullet. It's not any single component...it's ALL of them, plus the details that go into tuning the cartridge in question to the specific firearm it's to be fired from AND the conditions under which it's to be fired. In tandem, these factors determine the various ballistics of a given bullet, with the ultimate performance measure being terminal ballistics.

All of this meaning that accuracy is a holistic approach to an entire system.


It seems to me that all these accuracy claims are based on established conditions and setups, outside of which this kind of performance is not achievable with such a cartridge as the 6mm PPC USA. Take benchrest shooting to longer ranges, such as the 1,000 yard range, and this cartridge no longer dominates like it does at 100, 200, or whatever shorter ranges.


So I'm not buying this "inherently accurate cartridge" thing. What you have is a holistic system which works together to achieve a given accuracy standard.

 

[tipoc]

A cartridge is a combination of primer, brass, powder, and bullet. It's not any single component...it's ALL of them, plus the details that go into tuning the cartridge in question to the specific firearm it's to be fired from AND the conditions under which it's to be fired. In tandem, these factors determine the various ballistics of a given bullet, with the ultimate performance measure being terminal ballistics.

All of this meaning that accuracy is a holistic approach to an entire system.


It seems to me that all these accuracy claims are based on established conditions and setups, outside of which this kind of performance is not achievable with such a cartridge as the 6mm PPC USA. Take benchrest shooting to longer ranges, such as the 1,000 yard range, and this cartridge no longer dominates like it does at 100, 200, or whatever shorter ranges.


So I'm not buying this "inherently accurate cartridge" thing. What you have is a holistic system which works together to achieve a given accuracy standard.

Yes and at that point you have a cartridge that in relationship to another is "inherently" more accurate than the one you are comparing it to. What you have done above is describe the only setting in which one cartridge can exceed the performance of another and in doing so is "inherently" more accurate. Or to look at it another way, you assume the correct rate of twist, assume a quality rifle, scope, shooter, etc. Then you have a case, powder, bullet, primer etc. that together exceed the performance standards of it's competitors. At that point round x is more accurate then round y.

It may be that the "inherently" throws ya. That simply means that one round by it's characteristics, nature or makeup has the potential for greater accuracy than another, of it's class in the tasks it is designed for, if the other applicable factors are equal.

The term in general is overused. In being overused looses for many any sense of useful meaning.

tipoc

 

[RetiredUSNChief]

Yes and at that point you have a cartridge that in relationship to another is "inherently" more accurate than the one you are comparing it to. What you have done above is describe the only setting in which one cartridge can exceed the performance of another and in doing so is "inherently" more accurate. Or to look at it another way, you assume the correct rate of twist, assume a quality rifle, scope, shooter, etc. Then you have a case, powder, bullet, primer etc. that together exceed the performance standards of it's competitors. At that point round x is more accurate then round y.

It may be that the "inherently" throws ya. That simply means that one round by it's characteristics, nature or makeup has the potential for greater accuracy than another, of it's class in the tasks it is designed for, if the other applicable factors are equal.

The term in general is overused. In being overused looses for many any sense of useful meaning.

tipoc

Yeah, the term "inherently" is throwing me on this.

I don't see this example as "inherently"...one cartridge that performs better than another isn't "inherently" better just because it performs better.

"Inherently" means there is some intrinsic nature to the cartridge, different than any other cartridge out there, that makes it better at what it does.

For example, one can say that a cartridge that uses a steel core bullet is "inherently better" at armor piercing than a lead bullet because of the intrinsic characteristics of the steel core bullet as compared to that of a lead bullet.

One can say that a rifled long gun is "inherently more accurate" than a smooth bore long gun because of the intrinsic characteristics of a rifled barrel design which gyro-stabilizes the bullet in flight.


So when someone says a given cartridge is "inherently accurate", then there should be some aspect of that cartridge which has an intrinsic characteristic which makes that cartridge "accurate". By design, there's nothing special about any of the cartridges that have been discussed over any other cartridge out there...it's nothing more than fine tuning the elements which make up the cartridge in question.

And the "intrinsically accurate cartridges" are STILL tweeked in order to get the accuracies people praise them for. They vary the loadings depending on the range and wind conditions, they size the cases to exactly match their rifle chamber they're shooting from, they shoot them from single actions instead of bolt actions, they neck-turn their cartridges...

All of which makes one wonder...if a particular cartridge is "inherently accurate", then why all these various tricks of the trade in order to get the "ultimate" in accuracies?


So, WHAT intrinsic characteristics of the components/construction of a particular cartridge makes it "inherently accurate"?

 

[redneck2]

Best example I can think of is a .22 Hornet vs. PPC. The Hornet is a perfect example of everything wrong in an accuracy cartridge. Brass is too thin to maintain correct tension (which affects powder burn). Powder column is long and skinny, (which affects powder burn). Sloping shoulder.

Best Hornet loads use pistol powders. Some loadings don't fill the case, which leads to inconsistent burn, and therefore inconsistent accuracy. One of the big things in accuracy loading is low SD. If you have air gap, that can really affect SD. This is the reason that magnums are typically not as accurate as benchrest calibers. More powder means more variation in burn due to the characteristics of smokeless, particularly ones used in magnums.

Hornets head space on the rim, which affects bullet alignment. Obviously affects accuracy if the bullet is bouncing off the side of the rifling. This is why so many Rugers have awful accuracy.

.22 PPC/.222 can shoot the same exact bullet and will typically be far more accurate. A .22 Hornet that shoots sub 1" groups is much more rare than one that shoots over that. And, I'm not a Hornet hater, I just got one. I just understand what I'm up against. I sold a Ruger that was awful to get a CZ, which addresses your comment about barrels, rifling, etc. Some (probably most) Ruger rifles have crappy headspace.

Accuracy is the sum total of the parts involved. I can't slap a set of Goodyear racing tires on my Jeep and run Daytona.

 

[natman]

Yeah, the term "inherently" is throwing me on this.

Inherent in this context doesn't mean that the cartridge will be accurate no matter what. It means more or less what you said it means:

"Inherently" means there is some intrinsic nature to the cartridge...... that makes it better at what it does.

Please note that I removed the phrase "different from any other cartridge". As you noted, the title of the most inherently accurate cartridge has moved as cartridges have evolved, but all the cartridges you listed (222 rem, 22BR, 6mm PPC, etc) can be said to be inherently accurate.

 

[HankB]

In terms of rifles, the general consensus among benchrest shooters is that, within reason, short fat cartridges will generally produce better groups than long skinny cartridges with the same powder volume, assuming both ammo and rifle are built to the same tolerances. Short, fat, powder columns produce more consistent pressure curves.

It's rare that the winner's circle at benchrest matches is populated with long skinny rounds, which lends credence to the accuracy advantage assertion for short, fat cartridges.

Some claim that things like shoulder angle and case taper are very important, but evidence for that is more tenuous.

In pistol terms, it's hard to say how much accuracy comes from the cartridge, and how much comes from the gun. As just one example, for decades the .38 Super was thought to be an inaccurate cartridge; much of this came from the original headspacing, which was on the round's very small rim. (Some termed it a "semi-rim.") But when the .38 Super began to be used in "practical" competition, some 'smiths decided to build their guns so it would headspace on the case mouth, like the .45 ACP; suddenly, groups tightened and the round would hold its own.

 

[Ankeny]

Dan Lilja has an interesting article on his website about building precision barrels. He flat out says, "Some cartridges are inheriently accurate". I have been torld the same by the folks at Krieger Barrels. Other top barrel makers are of the same opinion, as are the makers of the most accurate competition rifles in the world. Cartridge designers like Mike at DTI have a pretty good idea of what makes a cartridge inheriently accurate. Then there are all of those world class shooters... I guess folks just need to consider their sources of information. Or maybe some of these guys are just trolling.

So, WHAT intrinsic characteristics of the components/construction of a particular cartridge makes it "inherently accurate"?

That horse has been beaten to death and then some. The answer to your question can be found at 6mmBR. com, Accurate Shooter.com, precision reloading, and so forth.

 

[tipoc]

Following up on Arkeny's post I went looking for his reference. It seems useful here. It appears in and article by Lilja on what he believes goes into an accurate rifle barrel. He describes the interplay of a number of factors...

Some cartridges are inherently more accurate than others. Very few benchrest shooters would deny that the 6PPC or variations of the same cartridge in .224 caliber are the most accurate rounds ever developed for shooting out to 200 and 300 yards. The flip side is that some cartridges are not as accurate.

It seems as though some experienced shooters and gunsmiths tend to place too much emphasis on one single characteristic of barrel as it relates to accuracy...

In our opinion this is putting the blinders on, a case of being myopic. All of these properties are important and a serious problem with any single one of them could cause accuracy trouble. But the point is they're all important. To sum up the critical factors we've mentioned, they include: a straight hole of uniform diameter and correct size for the intended caliber; a smooth and uniform surface finish that lays parallel to the rifling; a uniform rifling pitch; stress-free steel; adequate stiffness for the type of shooting it will be used for; and a first-rate installation job with special attention paid to the throat. An accurate barrel is the result of a happy marriage of all of these.

The italics are mine.

http://www.riflebarrels.com/articles/barrel_making/rifle_barrel_accurate.htm

A similar interplay of factors make up a bullet whose accuracy appears "inherent". I believe most of those factors have already been described in this thread.

He has a useful article on long range hunting and shooting that deserves to be read. The section on Cartridges and Bullets may be helpful. Was to me anyway.

http://www.riflebarrels.com/articles/longrange_shooting/shooting_hunting.htm

tipoc

 

[SilentStalker]

Simply put, "there is a reason why the 6mm stuff is so popular at long range comps all over the country." It's not a fad!