Most "efficient" cartridge for each caliber?

[H&Hhunter]

After toting an '06 all over the mountains of Colorado a few years ago, and getting punished by it (in a 6.5 lb. rifle) on the range all fall, I drew the same conclusion. For the distances I plan to shoot, the .308 was plenty of rifle for me.

I am not throwing shade at you in any way here.

The difference in recoil for a given bullet weight between a .308 and a .30-06 in a similar stocked and weighted rifle is unnoticeable to me. We as shooters tend to make mountains out of mole hills on a regular basis. I’ve got a buddy who absolutely losses his mind over 50 FPS difference between book and actual velocity for a given load. In his mind that’s the difference between success and failure.

Shooters allow insignificant and inconsequential numbers to rule their imaginations with all too awesome frequency.

 

[jmorris]

In effect, it’s defining the answer by overconstraining the question, such the question isn’t a question.

This is what many do with data.

 

[Varminterror]

The most efficient cartridge is the one that does the job at hand , reliably, with the least amount of brass , lead , copper ,and powder .To my mind Karamojo Bell's .275 Rigby ,or some poachers 7.62x39 , are the most meaning full efficient cartridges to date .

The only cartridges I know of that really seem to get ahead on efficiency seem to be the '06 Ackley cartridges , loaded with the same powder and bullet , at the same pressure they seem to do the same as belted magnums with less powder . As long as barrel length is under 26 inches. But this is from loading manuals and internet info , i don't have the rifles and equipment to test it out myself . I'd like to see a real world comparison between a 6.5-06 A and a 264 win , same components ,both at 65,000 psi , and a 280 A ,using 270 win brass for strength , again at 65,000 psi against a 7mm rem .

You need some newer books. Most of these cartridges have long been dethroned by more efficient cartridges (cough smaller cases, cough cough) which nearly meet, and in some applications exceed these older designs.

 

[denton]

First principles:

Efficiency = (productive energy)/(productive energy + wasted energy)

Efficiency is 1, or 100%, if wasted energy = 0. If wasted energy equals productive energy, efficiency is 50%. Energy stored in the compressed gas is lost to propulsion when the bullet uncorks the barrel. That is waste energy, which diminishes efficiency.

Don't confuse efficiency with effectiveness. Many of our most effective cartridges waste a lot of energy, and are inefficient.

 

[Newtosavage]

I am not throwing shade at you in any way here.

The difference in recoil for a given bullet weight between a .308 and a .30-06 in a similar stocked and weighted rifle is unnoticeable to me. We as shooters tend to make mountains out of mole hills on a regular basis. I’ve got a buddy who absolutely losses his mind over 50 FPS difference between book and actual velocity for a given load. In his mind that’s the difference between success and failure.

Shooters allow insignificant and inconsequential numbers to rule their imaginations with all too awesome frequency.

No shade assumed.

The difference in recoil for me was real. A stout load in a 6.5 lb. (scoped) '06 produces about 30 ft. lbs. of recoil energy. A stout load in a .308, about 23 ft. lbs. All for about 50 fps. in velocity. To me, it just wasn't worth taking the beating over for 50 fps. and I am not willing to carry a heavier rifle up to and over 10k feet.

Due to the higher BC's of 7mm bullets, my .284 Win delivers the same weight bullet at the same velocity beyond a certain distance with even less felt recoil. I shoot rifles better when they recoil less. Most people do.

 

[Newtosavage]

To me, "wasted energy" comes in the form of recoil felt and powder used, relative to what the projectile you are delivering is capable of.

 

[Varminterror]

To me, "wasted energy" comes in the form of recoil felt and powder used, relative to what the projectile you are delivering is capable of.

This is really not an efficiency.

As @denton and I both described, efficiency is a calculation of potential energy put into the system vs productive energy output by the system.

A relative yield of energy per recoil (itself again, as I’ve said several times, a trivial assessment yielding an empty set because it requires subjective input as well as interdependent variable overconstraint to define the boundaries of the system) isn’t really an efficiency.

As shown in this thread, we know trends for ACTUAL efficiency: small case, large bore, high pressure = more efficient than large case, small bore, low pressure… so when you build a true calculator, it yields dumb things like straight wall cases. So then you decide you have to “fix the problem” by adding various constraints like down range energy minima, and add things like rifle recoil maxima, with constraints on the rifle weight as a new independent variable - which really has nothing to do with the cartridge itself… so in the end, it’s overconstrained and subjective, because the math points to something you don’t like, so you make the math tell a different story by convoluting the algorithm.

The end result here is basically akin to a Facebook quiz which tells you which Breaking Bad character you are… a novelty at best.

 

[Newtosavage]

This is really not an efficiency.

As @denton and I both described, efficiency is a calculation of potential energy put into the system vs productive energy output by the system.

A relative yield of energy per recoil (itself again, as I’ve said several times, a trivial assessment yielding an empty set because it requires subjective input as well as interdependent variable overconstraint to define the boundaries of the system) isn’t really an efficiency.

As shown in this thread, we know trends for ACTUAL efficiency: small case, large bore, high pressure = more efficient than large case, small bore, low pressure… so when you build a true calculator, it yields dumb things like straight wall cases. So then you decide you have to “fix the problem” by adding various constraints like down range energy minima, and add things like rifle recoil maxima, with constraints on the rifle weight as a new independent variable - which really has nothing to do with the cartridge itself… so in the end, it’s overconstrained and subjective, because the math points to something you don’t like, so you make the math tell a different story by convoluting the algorithm.

The end result here is basically akin to a Facebook quiz which tells you which Breaking Bad character you are… a novelty at best.

And yet, here you still are...

 

[redneck2]

The thing most knowledge challenged wannabe designers overlook are those pesky laws of physics. Somehow changing the case capacity 2 grains and changing the shoulder angle half a degree makes the sooper, dooper Whizbang Ultra Mag into a magical round

As Solomon wrote maybe three thousand years ago, there’s nothing new under the sun.

Whether it’s a race car, speed boat, or bullet the laws of physics say that it takes more and more to get less and less.

 

[Newtosavage]

The thing most knowledge challenged wannabe designers overlook are those pesky laws of physics. Somehow changing the case capacity 2 grains and changing the shoulder angle half a degree makes the sooper, dooper Whizbang Ultra Mag into a magical round

As Solomon wrote maybe three thousand years ago, there’s nothing new under the sun.

Whether it’s a race car, speed boat, or bullet the laws of physics say that it takes more and more to get less and less.

Right, I think we all agree on that. So the question I had in my mind was, where is the "sweet spot" for each caliber?

 

[Grumpy_old_Fart]

Right, I think we all agree on that. So the question I had in my mind was, where is the "sweet spot" for each caliber?

I guess that would depend on application...

 

[Newtosavage]

I guess that would depend on application...

But even then, why would you choose an '06 for bullets under 150 grains, for instance. Bore size and bullet weight and powder capacity are of course all related. Like a triangle, there are balanced triangles and then there are unbalanced ones.

 

[Nature Boy]

My definition of efficiency = getting the desired results (accuracy) with the least amount of effort (time spent at the loading bench)

As I have defined it, the 6 BRA is the most efficient. Multiple load combos all shoot small and I have to really squint hard in load development to pick the best.

 

[NMachine]

Let’s just face it. This is the way cartridges are evolving. Even though nothing has really changed much in the last 50 years. But...but....but....BC, SD, and short action rules!

 

[Varminterror]

Whether it’s a race car, speed boat, or bullet the laws of physics say that it takes more and more to get less and less.

For all of these: “There’s no replacement for displacement!”

 

[Varminterror]

where is the "sweet spot" for each caliber?

There isn’t a “sweet spot,” because such can’t be defined without subjective restrictions which nullify the exercise. If “the sweet spot” for Bill isn’t the same as “the sweet spot” for Ted because they pick and choose parameters they like, then it’s just a subjective video game, not mathematical analysis.

But even then, why would you choose an '06 for bullets under 150 grains, for instance. Bore size and bullet weight and powder capacity are of course all related. Like a triangle, there are balanced triangles and then there are unbalanced ones.

Lost me on this one - all triangles have a centroid…

 

[Newtosavage]

There isn’t a “sweet spot,” because such can’t be defined without subjective restrictions which nullify the exercise. If “the sweet spot” for Bill isn’t the same as “the sweet spot” for Ted because they pick and choose parameters they like, then it’s just a subjective video game, not mathematical analysis.



Lost me on this one - all triangles have a centroid…

Again, you're still here.

And what I meant with the triangle analogy is which type of triangle contains the most area within it?

But yes, there is a sweet spot for each of us. You're taking things too literally. If Bill and Ted choose their own parameters, I think that's a good thing.

 

[redneck2]

But even then, why would you choose an '06 for bullets under 150 grains, for instance.

Most likely because I’ve already got a .30-06, and I like it, and whatever I’m going to shoot requires flat shooting and minimal penetration

And, I was incorrect previously. I had said a .22 short was the most efficient. Actually, it’s a CB cap

 

[Varminterror]

And what I meant with the triangle analogy is which type of triangle contains the most area within it?

Lost me again here. The area formula for triangles is the same regardless of type. h*b/2. So the answer to “which type of triangle contains the most area?” is “the bigger triangle.”

Feeling like math should work out doesn’t make math work out, especially when you try to make math have feelings.

 

[film495]

interesting topic. one element of it is also - how much flexibility you have for various functions in a particular cartridge. then the variation between powders for cartridges, which is why some are very common for specific cartridges. then application plays a role, paper targets is one thing, then there's actual down range velocity - say, difference between deer, elk, and a moose ... at whatever range you're at, there's a point where 30-30 is great for deer, to 100 yards and is more efficient than 30-06 .. but if you are looking at larger game at longer distance, efficient is good - but, I'd think the extra case capacity of 30-06 would be an advantage to say .308 .. all great cartridges, but all different. If I had to hump around any firearm for any period of time, out of what I have, it would be my Dad's old Ithaca 37 Featherweight, 20 gauge. I think I could take a deer with it at 50 yards, and it feels far lighter than anything else I own, so - to me that would be the most efficient, or I could carry it longer and farther than the others ... lol

 

[Newtosavage]

Lost me again here. The area formula for triangles is the same regardless of type. h*b/2. So the answer to “which type of triangle contains the most area?” is “the bigger triangle.”

Feeling like math should work out doesn’t make math work out, especially when you try to make math have feelings.

Sorry. It's been 30 years since I had college Calculus, surveying and trig. I know what I'm trying to say but have forgotten the terms.

Anyway, you're here to be objectionable and haven't offered much, so I'm just going to ignore your input on this topic from here out.

Plenty of others feel this is an interesting topic, so I'll just continue to discuss things with them. You can humor yourself by reading the comments of all of us easily misled people if you so choose.

 

[Newtosavage]

Ah, I meant equilateral when I said "balanced" triangle, meaning each side is equal in value. That produces the most area within the triangle unless you grow the entire triangle. But that's what the parameters are for - to establish some user-defined limits.

 

[Archie]

The question of 'most efficient' can be misleading. Is the most efficient automobile the one that gets the best gas mileage, the fastest, or the one that will carry the most people? Depends on what one wants.
'Most efficient' in a firearm is much the same.
The OP defined 'most efficient' as the cartridge that gets the most velocity per weight of powder. Which is a reasonable way to judge such. It is much like gas mileage in an automobile. The answer is rather simple. The smallest cartridge case (volume) in a given caliber will usually give the 'most velocity per grain of powder'. F'rinstance, a .22 Hornet will show much better figures than a .22-250. That the .22-250 usually shoots bullets of higher weight is immaterial to the question as stated. I'm sure the answer would be different were the criteria 'most velocity per bullet weight'.

As noted, that (velocity per grain of powder) is not universally celebrated. Efficiency may be tied to long range target shooting, or taking game that will stomp and eat one.

Or self defense. I prefer 'momentum' as a gauge as opposed to 'kinetic energy'. I am sold on the idea a heavy, wide bullet is more 'efficient' at rendering an assailant 'harmless' than a faster but lighter bullet. That's not to begin a side discussion, just an example of how 'efficiency' might be viewed.

Back on page one of this discussion, Varminterror commented he has never considered 'efficiency' as a criterion. Certainly not the sense of 'powder mileage'. From his screen name I would conclude his idea of 'efficiency' (whether he refers to it that way or not) is 'the ability to hit and dispatch a varmint'. Which takes in a whole host of factors, none of which are the smallest powder charge.

To address the initial question; probably .22 long rifle is about efficient as it gets. For center fire cartridges, .25 ACP has to be high on the list.

 

[Double Naught Spy]

This is a false assumption.

Recall, the pressure at the muzzle is only the result of the remaining force after expansion of the propellant gases. The bullet has already been accelerated, such it has a certain velocity, and all remaining pressure which exceeds the drag force imparted by the bore on the bullet remains an accelerating force. It’s fair to assume 1psi isn’t sufficient to overcome bore friction, but it’s not fair to assume that the bullet will have decelerated to the point of ineffectiveness. Expansion ratio, maximum in-bore inertia, and bore drag will dictate how much the bullet is decelerated as the driving force falls below that of the drag force (reminding, the slower the bullet goes, the less drag force it experiences, so it’s a differential system). If a small case pushes a bullet with a short bearing surface to 4000fps in bore, it could potentially still have greater than 2k muzzle velocity in an exceptionally long barrel even if the muzzle pressure has reduced to near-atmospheric pressure.

This is a false assumption. 1 psi will not overcome bore friction, but let's go with 0.1 psi or 0.01 or be really efficient with 0.000001 psi.

Anybody who as experienced a squib will be familiar with the force need to remove a bullet from a barrel.

Near squib loads are about as close as you will get to near zero pressure at barrel exit and they don't do well down range.

To quote John KSa
So, the issue isn't whether the pressure is increasing or decreasing, the issue is whether the pressure is pushing on the back of the bullet with more force than the combined forces that are trying to slow the bullet down. Whether the pressure is increasing or decreasing, the bullet will accelerate as long as the force on the back is greater than the combined slowing forces. Whether the pressure is increasing or decreasing, the bullet will slow down if the force on the back of the bullet is less than the combined slowing forces.
https://www.thehighroad.org/index.php?threads/can-a-bullet-slow-down-before-leaving-barrel.846053/

So you can make a barrel so long that the pressure will be near zero at the end or reduce the powder so far for a standard barrel that the pressure will be very low when the bullet exits, but those bullets are not going all that fast.

 

[Newtosavage]

So this really wasn't intended to be question of what the most efficient cartridge of all time is.

Rather, I'm curious - and feel free to state your opinion - what any of you would consider the optimal cartridge for each caliber. As I've already said, I find few faults whatsoever with the 7mm-08/7x57. It just seems to perform work well above it's weight class. Less powder capacity doesn't gain you much in terms of shootability. More powder doesn't gain you much in terms of downrange performance.

For a shoulder-fired weapon, it may be the ideal cartridge but then I'm sure Mr. Mauser figured all that out 130 years-ish ago.