Understanding cartridge efficiency

[degreen]

If a person was to take two cartridges that have the same case capacity, but one is considered more efficient than the other. What are the pro's of the more efficient case?

 

[FEENIX]

 

[dfanonymous]

If a person was to take two cartridges that have the same case capacity, but one is considered more efficient than the other. What are the pro's of the more efficient case?

What are the two cartridges?

 

[FEENIX]

What are the two cartridges?

L L! That's why I responded as such.

 

[degreen]

Any two of the same caliber, and same case capacity. Just one is considered more efficient than the other.

 

[dfanonymous]

Any two of the same caliber, and same case capacity. Just one is considered more efficient than the other.

Well an example would be a 260 and a 6.5 creedmoor have SIMILAR cases but different cartridges don't tend to be exact...in my example of the creed and 260 rem, they are different, or they would be the same cartridge which they are not.

You are going to have to give specific cartridges to compare if you want any serious input. Not that it's impossible but I can't think of any caliber specific case that is the same as another cartridge but not that cartridge, and one is better than the other.

 

[FEENIX]

If a person was to take two cartridges that have the same case capacity, but one is considered more efficient than the other. What are the pro's of the more efficient case?

Any two of the same caliber, and same case capacity. Just one is considered more efficient than the other.

So, you do not have anything specific for us to respond to?

 

[dfanonymous]

L L! That's why I responded as such.

I was thinking "ahhh no...FEENIX got em on the first post of the thread." Lol

I'll hold my popcorn gif depending what happens.

 

[FEENIX]

Well an example would be a 260 and a 6.5 creedmoor have SIMILAR cases but different cartridges don't tend to be exact...in my example of the creed and 260 rem, they are different, or they would be the same cartridge which they are not.

You are going to have to give specific cartridges to compare if you want any serious input. Not that it's impossible but I can't think of any caliber specific case that is the same as another cartridge but not that cartridge, and one is better than the other.

Yep! I might have an example but it can get seriously controversial and I'd rather not get there unnecessarily. If the OP comes up with it, that's a different story.

 

[FEENIX]

I was thinking "ahhh no...FEENIX got em on the first post of the thread." Lol

I'll hold my popcorn gif depending what happens.

L L!

 

[degreen]

This is not quite what I'm talking about. I watched a video of a gentleman comparing the 300 WM and the 30 Nosler. In the video he found the top accuracy load for both. The 30 Nosler was faster. If I remember correctly he was able to load the 300 WM to the same velocity as the 30 Nosler. Does this make the 300 WM a more efficient cartridge?

 

[FEENIX]

This is not quite what I'm talking about. I watched a video of a gentleman comparing the 300 WM and the 30 Nosler. In the video he found the top accuracy load for both. The 30 Nosler was faster. If I remember correctly he was able to load the 300 WM to the same velocity as the 30 Nosler. Does this make the 300 WM a more efficient cartridge?

OK, that is much better, but they do not have the same case capacity (.30 Nosler has the edge, it also varies from brass manufacturer). Below is a test extracted from another site but he is also a member here ...

At least we are on to something. If you do a search BROZ did a comparison between the two. The efficiency between the two is purely relative to the end-user.

The .30 Nosler vs .300 Weatherby (in terms of case capacity, but of course varies in brass manufacturer) might be a better comparison.

 

[P7M13]

Long winded, and forgive me if you already know this.
As a reloader, cartridge efficacy is what gives me the best brass life, minimal maintenance, and outstanding performance. Some of the things that enable that are 35° or 40° shoulders, long enough necks for good bullet seating and minimal runout, slight taper for easier extraction without increasing rearward force on the bolt face, excellent magazine fit and feed capability, etc. These are many of the things that P.O. Ackley did in his case modification experiments.
An internal ballistician can tell you about efficiency. Borrowing a page from the Manhattan Project, if you really wanted to maximize the efficiency of your cartridge, you would "shape" the powder charge and load the cartridge with layers of powders of different burn rates and charge densities, focusing the shock wave. Problem is, you'd probably pulverize the bullet before it even left the chamber. Bullets are cheap. Quantity thereof and the quality of their use tends to win.

Seems to me, in your thirst for efficiency knowledge, you are asking about same powder charge, same bullet, different velocities. You may well know, the only way to test this would be same barrel/powder/bullet etc. I read posts here and on other forums where people are loading cartridges like 338 LM with the same powder, charge, bullet weight, primer and brass that I use, in a barrel 2" longer, and they're getting 200 FPS more muzzle velocity than I do. I scratch my head and wonder, WTH am I doing wrong? Mind you, their rig might be a Defiance action with Krieger or Shilen barrel, same twist and mine is a Savage 110BA. So, no matter what the cartridge might be capable of, YMMV.
All that said, I offer this comparison of 7mm Cartridges, the first two with similar case capacities, for your review:

 

[Stiltsville]

There is no such thing as cartridge "efficiency" as Handloader proved several years ago with their 300 WSM vs 300 H&H test.

Roy tried to peddle this BS in the 1950s and people fell for it. They still do.