What's the most efficient center fire cartridge?

I used Quickload to figure out some stuff.

My suspicion that the allowed chamber pressure is a big input was spot on. The higher the better. As long as you are going to stay in SAAMI limits, the 65,000 psi rounds are going to win.

I also figured that fast burning is more efficient than slow burning. I was not sure if "high energy mattered, so I ran both TiteGroup (TG) and Red Dot (RD). Faster trumps high energy.

I was also correct that the heavier the bullet the better (as long as it is still accelerating when it get to the muzzle).

FYI, I knew the 308 did not stand a chance, but I ran it anyway with a normal powder. I re-did it with a 220 gr bullet and RD but it only increased to 82 ft-lbs/gr.

I also found that big cases reduce potential max efficiency. The 300 Rem Ultra Mag is higher pressure than the 308, but it maxed out at 57 ft-lbs/gr with the 220 gr bullet and RD.

Here is a summary (all with 20" barrels):

Triple Deuce.

I was going to say the 22 Hornet before anyone had done the actual calculations and posted them. It has always been a good performer with LilGun and a heavy bullet for me.

Demi-human said:

The undisputed king of straight wall cartridges!

And evidently the least wasteful as well, the 22LR!

Click to expand...

higgite said:

Read the topic heading again.

Click to expand...

Even though it's a Rim fire, honorable mention should be afforded this old guy...22lr
I have heard it has put more meat on the table and put down more critters than any cartridges, and besides...you can fit a bunch of them in your pockets...

higgite said:

Read the topic heading again.

Click to expand...

D’oh!
Rimfire on the brain, my bad.

They are exceptionally efficient at providing fun and shooting enjoyment.

Too ambiguous to answer.
Most foot-pounds of kinetic energy per unit of powder? Is that a particularly useful criteria? The simple way to determine this is to divide foot pounds by grains of power used. Rather tedious and repetitive. I would suggest a spread sheet application for this.

The most kinetic energy (of a consistent bullet weight) will be the loading that propels the projectile the fastest.
The most kinetic energy (of a consistent velocity) will be the loading that propels the heaviest projectile.

Your initial question and none of the calculations include the caliber (diameter) of the bullet (projectile) or the construction of such bullet.

What point does all this serve? What are you trying to determine?

Archie said:

Your initial question and none of the calculations include the caliber (diameter) of the bullet (projectile) or the construction of such bullet.

What point does all this serve? What are you trying to determine?

Click to expand...

I have to agree, just seemed like something different to do waiting on the next “what progressive?” thread.

Don't forget that all powder do not have the same potential energy per unit mass. In an effort to effect burn rate the propellent may be single base or double base in various ratios and have additives added to accelerate or retard that burn as needed for the application. Vihtavuoir N32C Tin Star only has 3040 kJ/kg where Alliant Power Pistol has 5150 kJ/kg. So calculating resulting ft-lbs of kinetic energy per grain of propellent is not a very accurate measure, given that some powders can have significantly more or less potential chemical energy per unit mass than a different propellent.

Y'all need to get out of the house more.
Im going hunting.

J .....Out.....

300 HH is more efficient than 300 win mag
IMHO
But I think I read a couple of years ago where some new midget 300 mag? beat both of them out.
Doesn’t matter, 300 HH is my favorite.

South Prairie Jim said:

Y'all need to get out of the house more.
Im going hunting.

J .....Out.....

Click to expand...

Sounds like a good idea, me too.

South Prairie Jim said:

Y'all need to get out of the house more.
Im going hunting.

J .....Out.....

Click to expand...

Sure, rub it in.

Not only do you make light of the fact I’m waiting for eight 9 year old boys to show up for a birthday party, but you also show the fact that such little difference it makes, in a succinct fashion.

Well played, Sir. But the game of Oneupmanship is afoot! Be wary...

.50 BMG for the win

30mm for #2 with depleted Uranium core

I’ve heard this question of efficiency before... seems the consensus is that a shorter case and high pressure is better. But I can’t for the life of me figure out why that matters in the real world. Those rounds also usually mean short barrel life, expensive and uncommon factory ammo, a particularly ear-splitting crack, and other factors that make their real world “efficiency” quite a bit less. And I have never heard a deer or piece of paper complain that the hole was made with an “inefficient” .308 (or even, heaven forbid, a positively antiquated .30-06) instead of a particular WSSM or similar.

4000 ft 26 degrees

South Prairie Jim said:

View attachment 9809734000 ft 26 degrees

Click to expand...

But, what are you carrying?

...Oops, wrong thread.

shhh

AJC1 said:

45/70 same 552 bullet 14 grains unique for 1100 fos. It's only 1483 foot pounds but half the powder so way more efficient. That's 110 foot pounds per grain.

Click to expand...

I've got a few Unique loads with over 100 foot pounds per grain in .300 Blackout and they are just my generic subsonic plinking loads with a 200ish grain bullet. It seems like Unique is a pretty good candidate if looking for an efficient powder. You won't get top velocity but the fact that you use much less powder makes it efficient.

jmorris said:

308 was the highest on this list at 67 ft/lbs per grain.

https://blog.westernpowders.com/2016/07/looking-at-cartridge-efficiency/

The data in #8 would be 85 ft/lb per grain.

Post #5 is 53 ft/lb per grain.

Post #1 is 68.3 ft/lb per grain.

6mm BR with 31gn pushing an 87gn bullet 3000 fps with 31 grains = 56 ft/lb per grain.

A 22 hornet with 12.4 pushing a 45 gn 2900 fps is 67.7 ft/lb per grain.

My 9mm minor load using 3.1 gn of N310 pushing a 147 at 890 fps is 82.9 ft/lb per grain.

A 25 ACP with 1.3 gn pushing a 50 grain bullet 850 fps is 61.5

A 22 short CB pushing a 30.5 grain bullet 700fps with .36 grains of powder is 91.7 ft/lbs per grain.

Winchester Dynapoint .22 lr pushes a 40 gn bullet to 1155 fps with 1.12gn of powder, beating them all with 105.3 ft/lbs per grain.

Click to expand...

That article is using standard loading practices which cheaters like me will work around. 45/70 in a standard loading of 3031 would not be competitive against other cartridges. The reason I went to the length I did was to show in these times of low supply, you can operate safely and smart to achieve an objective. For those that hunt and cant find their normal loads, the old school manuals have answers to questions not asked a year ago. I would choose 2400 over unique in a 45/70 because I feel more comfortable with the volume of that powder in that huge case... these exercises drive a deeper understanding from my point of view and not just an argument. I enjoy discussing things with that goal in mind.

Mosin77 said:

I’ve heard this question of efficiency before... seems the consensus is that a shorter case and high pressure is better. But I can’t for the life of me figure out why that matters in the real world. Those rounds also usually mean short barrel life, expensive and uncommon factory ammo, a particularly ear-splitting crack, and other factors that make their real world “efficiency” quite a bit less. And I have never heard a deer or piece of paper complain that the hole was made with an “inefficient” .308 (or even, heaven forbid, a positively antiquated .30-06) instead of a particular WSSM or similar.

Click to expand...

High pressure also mean higher temperature which means the powder burns more completely and cleaner converting more of it to gas for pushing the bullet. The higher temperature also increases the speed of sound in the propellant gasses making them more effective at pushing the bullet and less energy goes into gas dynamics and losses pushing the gases down the barrel. This higher temperature is also what shorten barrel life burning away the barrel steel at a higher rate.

South Prairie Jim said:

Y'all need to get out of the house more.
Im going hunting.

J .....Out.....

Click to expand...

How did you do? Think I’m going to give these a pass tonight but I’m not asleep yet...



I’m not up to do the math on how efficient a round I should grab a gun so chambered.

I got skunked but it looks like you could start a BBQ pit

I’m going to go with .32sw as the most efficient that I personally load. I think that 25acp might actually beat it in efficiency though. You can nearly shoot a 32sw on primer only so a pinch of powder and you are getting some ballistics. The issue here is that the primer is not being considered as propellant. If we consider the primer as well then my answer changes to 9mm as it’s fairly high pressure with a light powder weight and gets respectable point blank energies.

What's the most efficient center fire cartridge?

If you define efficiency as doing the most with the least, then you're all wrong.
I'm loading 32ACP with 1.7gr of powder, which means I'm getting over 4,100 loads from a single pound of powder.