Powder Efficiency

[cosmic creepers]

Hi guys,

I've been trying to do some research online to see if anyone has tested physically this thing, or if my pea brain doesn't make sense.

In Gordon's reloading tool, and nearly every calculator I can find it appears to defy my common logic, but someone's got to have a reason.

Let's use two arbitrary examples.

24 inch barrel

.223 remington with a 75 grain Hornady BTHP

Assume everything the same except for powder

Both rounds seated to 2.250"

Both rounds loaded with a max charge of said powder.

One loaded with a max charge of sta-ball match 25.3 grains for a predicted velocity of 2850fps

Next loaded with a max charge of Ramshot Xterminator 22.7 grains for a predicted velocity of 2794 fps

Okay now the question is, when I plug those exact numbers in, regardless of powder selections, and change only the barrel length, the velocities look to be on a curve with barrel length and show no signs of efficiency for faster burn rate in the 18" or even 11.5 inch barrels.

One would think that a powder that is fully burnt in 6 inches of barrel would show less or zero drop in performance out of an 11.5 barrel, compared to the powder which is only 98 percent burnt in an 18 inch barrel which would be expected to show reduced performance out of the 11.5.

But what I often have is reduced performance on a curve which doesn't make sense.

Has anyone gathered the real chronograph info on a test like this?

I've got a test made up with sta-ball match, Xterminator, Accurate2495, and LT32.

They will be shot out of the 11.5 inch barrel and compared to the outputs of Gordon's reloading tool, but I only have an old chronograph and so I need a sunny day, so here I am tickling my curiosity on accurateshooter.


What do you guys know?

Big Phil
The Constitution is my Bible

 

[Gabe22BR]

So stick powder vs ball powder-
Apples. Vs. oranges

-Case density comes into play

 

[cosmic creepers]

So stick powder vs ball powder-
Apples. Vs. oranges

-Case density comes into play

Well, not exactly, it seems to be any powder regardless of shape.

I do have one example loaded up of a very large grain extruded powder vs three other ball **edit, I forgot about the LT32, so there are two extruded and two ball, but I doubt that will have any impact on what I'm trying to explore** but powders, but we are testing burn rate not powder shape here.

And testing whether faster powders are actually more efficient than slower powders for creating velocity in a shorter barrel.

Maybe come back this morning now that you've put your beers down and read it again, ai think the actual test went over your head, or else I didn't explain well.

 

[K22]

The key to your answer is the word "predicted".

Real test data will probably answer your question but then maybe not. If you have access to a Speer Reloading Manual, read the Article entitled, "Why Ballisticians Get Gray [Hair]. It will explain a lot.

 

[cosmic creepers]

The key to your answer is the word "predicted".

Real test data will probably answer your question but then maybe not. If you have access to a Speer Reloading Manual, read the Article entitled, "Why Ballisticians Get Gray [Hair]. It will explain a lot.

Well I'm going to the range with the chronograph right now, so I'll have an answer, hopefully by the afternoon

 

[Gabe22BR]

And testing whether faster powders are actually more efficient than slower powders for creating velocity in a shorter barrel.

Yes, powder doesn’t have as barrel to burn in-doesn’t take a genius to figure that out.

Maybe come back this morning now that you've put your beers down and read it again, ai think the actual test went over your head, or else I didn't explain well.

Case density comes into play-
Looks like that went over your head…

-223 isn’t very efficient to start with-
Good luck with those consistent Hornady bullets as well…


I don’t know much about gordon, just real world experience…

I’m using N202 in a 16” barrel w/ Barts 52gr bullets- in a Christensen arms bolt action …

 

[cosmic creepers]

Yes, powder doesn’t have as barrel to burn in-doesn’t take a genius to figure that out.


Case density comes into play-
Looks like that went over your head…

-223 isn’t very efficient to start with-
Good luck with those consistent Hornady bullets as well…


I don’t know much about gordon, just real world experience…

I’m using N202 in a 16” barrel w/ Barts 52gr bullets- in a Christensen arms bolt action …

How 223 isn't efficient?

 

[cosmic creepers]

If anyone has been interested in this, as I have, you can watch the process with My findings Here .

It seems that the amount of optimization that can be achieved from these macro adjustments is very minimal, which leads me to conclude that the maximum velocity that can be achieved is determined by the cartridge, bullet and powder, but it may not matter how long of a barrel you put onto it.

I had a harder time wrapping my head around it before I got my test results, but what would appear to be the case is this: the term internal ballistics is perhaps a bit of a misnomer. There seems to be chamber or cartridge ballistics and then barrel ballistics, perhaps internal ballistics is subdivided into these two groups.

It would seem that as we walk the fine line between burn, explosion, and detonation, we are playing a game of millionths of seconds, or milli-milli-seconds. In this game of milli-milli-seconds it would seem that the maximum velocity attainable is achieved in the chamber before the bullet even passes beyond engraving, and so it would seem to not matter whether the charge is burnt up in six inches or sixteen inches of barrel, that the rate of gas expansion, and therefore, velocity of that expansion was already determined long before that powder completed burning.

Although the difference in velocity may be more pronounced in slower powders, the maximum achievable velocity for a shorter length barrel can not be a load which achieves less than the max velocity in the longest barrel tested.

**grain of salt** I think when it comes to extremes of cartridge volume or barrel length, this would be an exception. (Imagine you made a .223 case that was 6 inches long and then put that cartridge into a 60 inch barrel)

But anything short of the extreme or audacious example, I would presumptuously assume that the results I got would be similar.

It just required me taking a look at the data from a different angle.

Thanks for coming out.

 

[Gabe22BR]

Powder column to bore size 222/221FB way more efficient-… in 22cal