Most ft./lb energy per grain of powder?

Palladan44

Palladan44

Member
Joined
Nov 7, 2020
Messages
1,903
Let's talk efficiency.
Obviously barrel length comes into play as well, but I wonder what handload (powder, bullet) fired out of what gun (barrel length) gives the most ft/lb of energy per grain of powder, and thus is the most efficient cartridge/firearm combo....
I'd have to think a bolt action carbine (so no gassing)of some sort, maybe 9mm w/115gr bullet loaded with a faster powder, maybe high nitroglycerin content....maybe bullseye.
Interesting thought.
 
Last edited:
The data is out there - whatever is the smallest cartridge, be it 22 short or something of its class, has the highest YIELD of ft.lbs. per grain. Not a very interesting result for the question asked, but it IS the answer.
 
You might ask yourself, WHY even ask this question, since it contains an obvious implied contradiction:

The energy content of a bullet in effect measures the potential killing power of the bullet, assuming of course that the combination of weight, caliber, and bullet shape is appropriate for the specific target and mission.

But as pointed out already in posting number 3 above, the highest yeild of energy per grain of powder is for a cartridge whose practical killing power is too low for any use beyond small, easily stopped targets at rather short distances. The most practical use for that cartridge is short range target shooting. So, that cartridge may be the most theoretically "efficient", but is going to be very limited in its overall suitability , especially to a handloader, since it cannot be reloaded!

A better question to ask is: If I want to (fill in type of shooting you want to do), and want to minimize my usage of powder, what cartridge should I use as my basis for developing a handload for my specific intended usage(s)?

If your intended usages vary (e.g. hunting a range of animal weights and sizes AND target shooting at varying distances ), and your budget limits you to one firearm and handloading for one cartridge, and you want to minimize your powder usage, and you want to avoid high rates of barrel wear, then an even more practical and focused question becomes: What cartridge in what firearm is the most practical choice for my needs and wants? THAT does get pretty interesting.

Jim G
 
My first thought is 45acp. That packs a lot of wallop per grain of powder.

Never really thought about efficiency of loading various rounds until I started loading for 9mm. Bang for the buck. A 124 grain jhp bullet at factory velocity blew up a gallon jug of water, then retained enough energy to pass thru a 2 cubic foot bundle of compressed peat moss........the long side. That is also a lot of wallop from 5 grains of powder.

And this is what 1,000 founds of 9mm looks like in the raw. With powder left over........

IMG_0915.jpg
 
The Quick Loads software (and maybe GRT) will tell you what percentage of the potential chemical energy gets turned into kinetics energy of the projectile for any particular load. It's usually pretty inefficient (on the order of 20-40% in most cases IIRC) from that point of view. Though in reality far more efficient and convenient than most of the alternatives.
 
The larger the bore and the faster the powder the more efficent.45c with red dot is moving a heavy large bore bullet with great energy for low powder usage. It could be used in a wide array of shooting activities from lever action Silhouette to hunting game. By the same token it's big brother the 45-70 does even more damage at moderate range. 37 grains of 4227 will put the hurt on inside 200 yards. That's a lot less than the 45 grains of 4064 I use in 308... as you step into bottle neck cartridges that effency plummets, and the more overbore the worse it gets.
 
AJC1 said:
The larger the bore and the faster the powder the more efficent.45c with red dot is moving a heavy large bore bullet with great energy for low powder usage. It could be used in a wide array of shooting activities from lever action Silhouette to hunting game. By the same token it's big brother the 45-70 does even more damage at moderate range. 37 grains of 4227 will put the hurt on inside 200 yards. That's a lot less than the 45 grains of 4064 I use in 308... as you step into bottle neck cartridges that effency plummets, and the more overbore the worse it gets.
Click to expand...

And, the worse the barrel life gets also.

Jim G
 
AJC1 said:
The larger the bore and the faster the powder the more efficent.45c with red dot is moving a heavy large bore bullet with great energy for low powder usage. It could be used in a wide array of shooting activities from lever action Silhouette to hunting game. By the same token it's big brother the 45-70 does even more damage at moderate range. 37 grains of 4227 will put the hurt on inside 200 yards. That's a lot less than the 45 grains of 4064 I use in 308... as you step into bottle neck cartridges that effency plummets, and the more overbore the worse it gets.
Click to expand...
According to Quickloads 37gr of 4227 under a 350gr bullet in 45/70 will turn ~35% of the chemical energy into kinetic energy of the bullet. Similarly 45gr of 4064 under a 168gr bullet in 308 Win results in ~ 34% of the chemical energy being imparted to the bullet as kinetic energy. Both using a 24 inch barrel. There are too many factors at play to state simply, big bores are more efficient the small bore etc...
 
mcb said:
According to Quickloads 37gr of 4227 under a 350gr bullet in 45/70 will turn ~35% of the chemical energy into kinetic energy of the bullet. Similarly 45gr of 4064 under a 168gr bullet in 308 Win results in ~ 34% of the chemical energy being imparted to the bullet as kinetic energy. Both using a 24 inch barrel. There are too many factors at play to state simply, big bores are more efficient the small bore etc...
Click to expand...

I think that the onyl reason the powder efficiency of the 45-70 is not better than that of the 308 is the low percentage fill of the huge 45-70 case, which was designed to accept black powder versus smokeless. That makes that particular comparison invalid right from the get go. I WOULD suggest comparing a 308 to a 6.5 Creedmoor. THAT comparison would be much more meaningful, and the barrel life statistics particularly so.

Jim G
 
mcb said:
According to Quickloads 37gr of 4227 under a 350gr bullet in 45/70 will turn ~35% of the chemical energy into kinetic energy of the bullet. Similarly 45gr of 4064 under a 168gr bullet in 308 Win results in ~ 34% of the chemical energy being imparted to the bullet as kinetic energy. Both using a 24 inch barrel. There are too many factors at play to state simply, big bores are more efficient the small bore etc...
Click to expand...
Your math says that 4227 is mire energy dense, which it is, but that doesn't change the price per grain. Are we talking cost or chemical energy? Or are we just talking number of grains extended. So many different directions to take that.
 
  • Like
Reactions: mcb
I am not so sure about the "bigger is better" position.

I was recently running some QL stuff looking for a "22 LR equivalent" centerfire squirrel gun round. Objective was for a very quiet round to be fired with no suppressor.

I ran some heavy subsonic 25 ACP ++P loads for use from a 16" TC Contender.

1.2 gr of TiteGroup under a 70 gr cast bullet gets 980 fps, with a chamber pressure of 48800 psi, a ballistic efficiency of 63.9% and a muzzle pressure of only 286 psi.
 
P Flados said:
I am not so sure about the "bigger is better" position.

I was recently running some QL stuff looking for a "22 LR equivalent" centerfire squirrel gun round. Objective was for a very quiet round to be fired with no suppressor.

I ran some heavy subsonic 25 ACP ++P loads for use from a 16" TC Contender.

1.2 gr of TiteGroup under a 70 gr cast bullet gets 980 fps, with a chamber pressure of 48800 psi, a ballistic efficiency of 63.9% and a muzzle pressure of only 286 psi.
Click to expand...

That IS impressive! And, particularly so when you do the math and see that the projectile has 149 ft lb of energy, and realize that many of the factory 9mm loads only have a bit over double of that! Now practical usage outside of your supressed squirrel hunting scenario is admittedly narrow. I can see the potential foir a whole new competitive varmint shooting sport: 25ACP at 100 FEET !

Jim G
 
FYI, I was talking about quiet without the tax stamp required gadget on the end of the barrel.

I did a little more what-if dreaming. Low muzzle pressures just sound so tempting. As a follow-up to the 25 ACP, I am really thinking hard about a shotgun insert:

Hmmm, a wildcat using shortened 5.7 x 28 brass and a 22LR pulled barrel is probably an easier route than the 25 ACP. I just so happen have the a pulled 22" long 22 LR barrel and a baggie of range pickup 5.7 x 28. Hmmm. Target parameters: 5.0 gr water capacity, 51 gr bullet, 0.93 gr TG, 94% fill, 201 psi at the muzzle. Hmmm. I need a shell holder. Hmmm.
 
You must log in or register to reply here.

Similar threads

S
  • Locked
What's the most efficient center fire cartridge?
2 3
Replies
50
Views
2K
hdwhit
H
Macchina
  • Locked
Interesting: Recoil due to powder weight.
2 3
Replies
55
Views
2K
Njal Thorgeirsson
N
R
  • Locked
Lead cast reloads and chronograph velocities for 9x19, 380 acp and 38 spl/357 mag
Replies
10
Views
652
Tcruse
T
E
  • Locked
Handloading for barrel length or suppressors
Replies
4
Views
955
AJC1
AJC1
T
  • Locked
LVR 30-30 load
Replies
7
Views
1K
kelbro
K
Back
Top