Caliber accuracy

Originally Posted By: SShooterZOriginally Posted By: CatShooterThere has never been a cartridge that uses 15% less powder than Cartridge B and gets similar results...

... it defies the laws of physics.

Cartridge performance is solely dependent on case volume, pressure curve, and barrel length (all other things being equal).




I don't want to argue with you because I respect your input, but I'll throw out this as an example.

Taken from the Hodgdon site:

6MM Remington - 58GR Hornady V-Max - 42.0 Grains of BL-C(2) for 3502 FPS

6MM BR - 58GR Hornady V-Mac - 35.0 Grains of BL-C(2) for 3386 FPS

So, its a 100 FPS difference, which I will admit, is a difference. Is it noticeable? Maybe to some, not so much to others.

But if my math is correct, that is a 15% decrease in powder with ALMOST identical results. (Pesky physics defying rounds..)


What you are doing is called "Cherry picking". You are picking unequal examples to prove a point. You CANNOT compare a maximum pressure performance load for the 6mmBR, to a starting load performance of a 6mm Rem, cuz it just does not work that way - Bad puppy!!!


You cannot compare one round working at 55 Kpsia, to another round working at 35 Kpsia - it is not done.

In order to compare rounds, they MUST be using the same maximum pressure, and be filled with a powder that has an optimum volume to pressure for the case and bullet.

You can't compare a 6mmBR using 8208, with a 6mm Rem using BullsEye, even though they are both loaded to 55 Kpsia.

The best BLc2 loads for the 6mmBR and the 58 V-Max... 33.5 of powder and yield 3386

The best BLc2 loads for the 6mm Rem and the 58 V-Max... 46.5 and yield 3930 fps.

That's ~ 544 fps difference - a whoppin' lot of difference.

If you want to compare "efficiency" - that is a 1.16% increase in speed form a 1.39% in powder... but in energy, it is a 1.36% increase of energy - so you have increased the powder by ~1.38 and gotten ~1.35% increase in energy - that is "unity" in efficiency...


You cannot compare apples to bananas
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Originally Posted By: CatShooterWhat you are doing is called "Cherry picking". You are picking unequal examples to prove a point. You CANNOT compare a maximum pressure performance load for the 6mmBR, to a starting load performance of a 6mm Rem, cuz it just does not work that way - Bad puppy!!!

Why? (Seriously, I am trying to understand this.)

And I was not cherry picking at all. I was looking for similarly performing loads. Hence the reason I asked in the first place about "efficiency" of a round and if that has any bearing on accuracy.

I agree, the pressure differences are there, but per prior conversation, that has no affect on accuracy correct?
 
Originally Posted By: SShooterZOriginally Posted By: CatShooterWhat you are doing is called "Cherry picking". You are picking unequal examples to prove a point. You CANNOT compare a maximum pressure performance load for the 6mmBR, to a starting load performance of a 6mm Rem, cuz it just does not work that way - Bad puppy!!!

Why? (Seriously, I am trying to understand this.)

And I was not cherry picking at all. I was looking for similarly performing loads. Hence the reason I asked in the first place about "efficiency" of a round and if that has any bearing on accuracy.

I agree, the pressure differences are there, but per prior conversation, that has no affect on accuracy correct?



If you want to compare cartridges, you cannot pick circumstances to fit what you are trying to prove.

You cannot compare a case that is full and working at 55,000 psi to a case that is 40% empty and working at 35,000 psi.

That shouldn't even need explaining.
 
when remington test fires thousands of guns in the same vice and tunnel, and the 220.swift is more accurate than the 22.250 to me this proves that some catridges are just better balanced or more effecient.look how long the 308 stood the test for the military.i read the thing bout the swift and 22.250 in some material from rm.a long time ago
 
"Friggin Engineers"...now wait a minute. When I went to engineering skool it was civil, mechanical, electrical, and industrial only. If they have added a new category I'm signing up for night classes.
 
Originally Posted By: UncleDoc"Friggin Engineers"...now wait a minute. When I went to engineering skool it was civil, mechanical, electrical, and industrial only. If they have added a new category I'm signing up for night classes.

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(anybody that didn't think that's funny needs to read it again)
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I went to school to be an "enginner". I'm still waiting on them to let me drive the train!


I've been watching this thread from the start. I knew it would get good. Quality componants & GOOD load development is more important than cartridge. That said, I am a FIRM believer that some cartridges have more accuracy potential than others... It may be to a point of being unseen (once your shooting itty bitty groups a substaintial improvement is still extremely small).

Comparing 1000 yard matches to an accurate "cartridge" seems hardly fair. A custom 66gr bullet out of a well built 6ppc has proven to be just as "accurate" as anything in the world, but don't do much @ at 1K. "Condition" cheating bullets help more there than being super "accurate".
 
Originally Posted By: CatShooterIf you want to compare cartridges, you cannot pick circumstances to fit what you are trying to prove.

You cannot compare a case that is full and working at 55,000 psi to a case that is 40% empty and working at 35,000 psi.

That shouldn't even need explaining.



Ok, I'll bite since this one is still going.
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Let's even the playing field per your advice.

.308 vs. .30-06

Couple of instances where the .308 uses about 10% less powder than the .30-06 with very similar results. (Similar pressures too) Also lots of talk about the "accuracy" of the .308 cartridge family. Is it because it is more efficient?

Is the .308 "inherently" more accurate than the .30-06. Maybe, maybe not. They can shoot the same bullets, use the same powder and utilize the same barrels. Action is really all that is different and even then, I'm sure there are more than a few who shoot a .308 in a LA.

Thoughts?
 
Originally Posted By: SShooterZOriginally Posted By: CatShooterIf you want to compare cartridges, you cannot pick circumstances to fit what you are trying to prove.

You cannot compare a case that is full and working at 55,000 psi to a case that is 40% empty and working at 35,000 psi.

That shouldn't even need explaining.



Ok, I'll bite since this one is still going.
grin.gif


Let's even the playing field per your advice.

.308 vs. .30-06

Couple of instances where the .308 uses about 10% less powder than the .30-06 with very similar results. (Similar pressures too) Also lots of talk about the "accuracy" of the .308 cartridge family. Is it because it is more efficient?

Is the .308 "inherently" more accurate than the .30-06. Maybe, maybe not. They can shoot the same bullets, use the same powder and utilize the same barrels. Action is really all that is different and even then, I'm sure there are more than a few who shoot a .308 in a LA.

Thoughts?

Not true...

.. and not true!
 
Originally Posted By: SShooterZOriginally Posted By: CatShooter

Not true...

.. and not true!



Which parts?

"Let's even the playing field per your advice.

.308 vs. .30-06

Couple of instances where the .308 uses about 10% less powder than the .30-06 with very similar results.

Not true.

"... Also lots of talk about the "accuracy" of the .308 cartridge family."

Not true! In equal rifles with equal components, both are equally accurate.

"Is it because it is more efficient?" No, and it is not more efficient (since it is not true!)

"Is the .308 "inherently" more accurate than the .30-06. Maybe, maybe not."

It is not!

" They can shoot the same bullets, use the same powder and utilize the same barrels. Action is really all that is different and even then, I'm sure there are more than a few who shoot a .308 in a LA.

Thoughts?

You got'em

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Originally Posted By: devildoggWhat makes one caliber more accurate than another? Wouldn't the rifle make the caliber more accurate more so than the caliber making the rifle accurate? Let's say for instance a 6br vs a straight up 243 win. What makes a 6br so accurate or a couple of years ago it was a 260 that was the caliber to have for long range shooting. Is it because the design of a specific cartridge is more efficient and burns the powder more uniformed than another? Thanx for any and all replies.



To answer your question in the best term I know how, you are splitting hairs. These days almost all chamberings are "accurate".

You are right in that the quality of the rifle components along with the quality of the machine work will make the most difference in accuracy potential. However, if I have a 222 Rem that is in "stock" form, with reloads that is bedded and floated, and you have a 6BR that is all equal except for the bedding and float job, My Deuce will probably out shoot you.

Things concerning accuracy these days can also come down to the quality of the glass your rifle is wearing, and the bugger behind the trigger.

If we compared the 6BR to the 243 Win, all things being equal, the best shot that day would more than likely win the day.

Alot of this is just plain "hype", and column writers trying to get readers. IMO.

It is true that some case "improvements" have been made over the years, but in the case of the 6PPC for instance, we are talking thousandths of an inch "better" accuracy than the old 222 Rem and some of that can be from the better B.C of the 6mm bullets.[better in the wind"

In long range shooting B.C is always King, but in 100yd benchrest not nearly as much. It is a deep subject and one that will take careful study to understand fully.

Best of luck.
 
Originally Posted By: devildoggWhat makes one caliber more accurate than another? Wouldn't the rifle make the caliber more accurate more so than the caliber making the rifle accurate? Let's say for instance a 6br vs a straight up 243 win. What makes a 6br so accurate or a couple of years ago it was a 260 that was the caliber to have for long range shooting. Is it because the design of a specific cartridge is more efficient and burns the powder more uniformed than another? Thanx for any and all replies.

What it's all going to boil down to is the type of shooting you are going to be doing. Some calibers offer a bullet selection that allows said cartrige to be applied from varminting to dangerous game, yet others will fall nearer either end of that spectrum. Within each cartrige there will be a range of bullet weights that due to velocity and barrel twist will be inherently more accurate than others. All of this meaning that any given cartrige is absolutely capable of < MOA accuracy, but it's all up to component selection and load development to extract the most from said cartrige. All of that is still limited by the gun it is fired from, and due to many things plain and simple, some guns will and some won't shoot MOA. Bottom line, shooting at 1000 yds, BC and SD make all the difference. At 300 yds not so much. Think the difference between a rock and an arrow, at 5' mot much difference in trajectory, now make that 500', well I hope you get the point.
 
Originally Posted By: CatShooter
"Let's even the playing field per your advice.

.308 vs. .30-06

Couple of instances where the .308 uses about 10% less powder than the .30-06 with very similar results.

Not true.

Some of the data from Hodgdon says otherwise. But I digress.

I understand everything else you're saying and have no reason not to believe it to be true.
 
I think its about tuneablity. Some cases or chamberings are easier to tune than others. In the short range game, there are a lot of followers, but not everyone is a follower, not by a long shot. If there was a more dominate chambering for shortrange Br other than a 6ppc, someone would have found it by now. The 6ppc is dominate because its easy to tune and because there is an abundance of good hand made bullets. We now have some good powders to use, and even some new inovation of powders to come. there is a hole cumminity associated around the 6ppc thus making the case easier to understand and easier to make it work. Also keep in mind we deal with weight limits in the short game. 10.5 pounds isnt very much weight. Even a great tuned up 243 wouldnt be a good idea in a 10.5 pound gun over the course of two days of shooting. i dont really think case design has a lot of merit, but it may have a little? Look at the 6mm remington. that case is nothing like a 6ppc, and those darn things can really shoot if tuned properly. In 600 yards you have the 6Br and dasher. Easy to tune and a hole suport community around it. mild recoil and fast follow ups never hurts either. These are just some of my thoughts and observations. Lee
 
Originally Posted By: SShooterZOriginally Posted By: CatShooter
"Let's even the playing field per your advice.

.308 vs. .30-06

Couple of instances where the .308 uses about 10% less powder than the .30-06 with very similar results.

Not true.

Some of the data from Hodgdon says otherwise. But I digress.

I understand everything else you're saying and have no reason not to believe it to be true.

There is a lot of conflicting data on the Hodgdon site - they are in the middle of going from CUP to Strain measurements, and they are NOT compatible nor comparable.
 
One thing to consider here is the difference in case volume to powder charge.

The 30-06 has ~68.2gr capacity, the 308 has ~56.0gr capacity.

That is ~18% less case capacity for the 308.

If I generically run the two through quick Load it looks like this;

308 win

55.Gr H-4831sc

55,223 psi

2810 fps

--------------------------------------------


30-06 loaded to 10% more powder than the 308.

60.5gr H-4831sc

44,491 psi

2745 fps

If the 30-06 is loaded to the same ~psi,

64.5gr H-4831sc

55,155 psi

2950 fps.

The reason for the Assumed extra efficiency with the 308 is because the case is within 1.0gr of fill capacity. That powder burn has no place to expand but down the barrel pushing the bullet in front.

In the case of the 30-06 @ a 10% increased charge over the 308, we see that chamber pressure is significantly lower, and that the case fill to capacity is much lower, within 7.7gr to fill capacity. The gasses in the 06 case have more room to expand and therefore create less pressure.

When loaded to equal pressures with this powder we see a gain of 140 fps to the 30-06. That is in "magnum" territory. The efficiency to get there is not the point, it is the performance gain. IMO, because of the amount of difference in case capacity between the two they are more like apples and oranges than comparable cases for efficiency.
 
Originally Posted By: CatShooterThere is a lot of conflicting data on the Hodgdon site - they are in the middle of going from CUP to Strain measurements, and they are NOT compatible nor comparable.

That part I knew. (CUP vs PSI) Came from the Shotshell reloading world for a long time before I got into cartridge. Hard to believe how much of that data is inter lapped. Seen a lot of arguments over that one too.

Smokeless great explanation. Thanks!
 
Im lost....i killed a deer at 300 yards with a weatherby vanguard chambered in .270 with a cheap centerpoint walmart scope and factory ammo...to me thats accurate enough. i guess if i was shooting quarters at 100 yards id be more interested in loads and trajectory and ballistics, i just want dead animals.
 


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