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Latest Relative Burn Rate Chart

p-man

Gold $$ Contributor
Does anyone have a link to an updated (late 2016) burn chart that includes the latest IMR Enduron powders and Reloder powders (16, 22, etc.)?
 
Wow, they really gussied it up, pretty colors! The Enduron powders are all in green.

Incidentally, I am working up a new 270 Win load with IMR 4451, which is sandwiched neatly between the two 4350 powders here. As it happens, with my rifles' throat, the 130-gr BT, seated just shy of the lands, intrudes only the boat tail into the case shoulder area, and a max load of 4451 just touches the base of the bullet. Not compressed, but 98% load density. And Hodgdon lists 4451 velocity the highest of the Hodgdon / IMR / Win powders behind a 130-gr lead core bullet. So I have high hopes ...
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wiuprof said:
This is the most current that I've seen.

https://www.hodgdon.com/PDF/Burn Rates - 2015-2016.pdf
Click to expand...

That is a good one, as it has the most recent powders. However, I always find that one hard to use. It kind of suggests that there are no powders that are essentially the same burn rate. The reality is that most manufacturers duplicate or pretty much duplicate the burn rates of powder that the other guys make. The Vihtavuori chart I actually like the best as it gives a good feel for the relative speeds. Too bad it hasn't been updated for a long time...

Vihtavuori Burn Rate Chart

The one I find most interesting though is the Norma one. It uses an interesting concept. They start with a base powder (IMR 4350) and assign it a velocity and pressure of 100%. Then they list what the various other powders get with the same charge compared to the base load. The down side is that it was done only in a 308, and the results may be most applicable to those who have a 308. One example of how it could be used is when you compare the base powder to say H4350. Velocity remains at 100% but pressure goes down to 95%. Based on this chart is obviously the better powder.

Norma Burn Rate Chart

Too bad that the Norma chart does not include more of the powders. Unless I missed it a prime 308 powder, Varget, is missing...
 
You do realise that certain powders will swap depending on the cartridge a powder is used in?
Burn rates are from a relative quickness test called a calorimeter bomb, it measures the heat and pressure a certain pre-determined charge weight makes in a pressure vessel, this vessel is not damaged during this test. Peak pressures are taken, along with time and energy figures.
Now, with no set standard as to charge weight, size of vessel and other factors, no 2 powder manufacturers results will be even close to each other.
I know for a fact that IMR4895 is given an RQ rating of 100, if a powder is faster than this, it gets a higher number, if it's slower, it gets a lower number. How this corresponds to other manufacturers, nobody knows, as each one uses different methods.

Cheers.
 
brians356 said:
WTF? This link no longer points to the new colorized chart, w/ for example the Enduron powders in green. I wonder what happened?
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Click to expand...

There are times that I feel really handicapped by being color-blind. But at times like this, I feel that it is a "blessing in disguise" because I have no idea what the heck you're talking about!!!
 
wiuprof said:
There are times that I feel really handicapped by being color-blind. But at times like this, I feel that it is a "blessing in disguise" because I have no idea what the heck you're talking about!!!
Click to expand...

On 7 November I followed that link and Surprise! the old burn table was gussied up, with color coding for all the powder families, larger and more readable font, etc. It just jumped off the page. Even with no color discrimination, you would have noticed the difference. Alas, while newer powders like Enduron 4451 are in there, it has reverted back to the old format. I can't imagine why.

PS Here's a bulletin from this very forum, announcing the new color chart. But if you click on the chart, it now takes you to the old B&W Hodgdon chart.

http://bulletin.accurateshooter.com/2016/01/updated-hodgdon-and-imr-relative-burn-rate-chart/

Here's a PDF of the color chart (no longer accessible at Hodgdon):

burnchart1601op.png
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Last edited:
I put very little faith in listed powder burn rates. They are accurate representations of the burn rate in a confined space ignited at a specific temperature and nothing more. The rate at which they burn in a chamber of a gun can be entirely different.
 
SheepDog said:
I put very little faith in listed powder burn rates. They are accurate representations of the burn rate in a confined space ignited at a specific temperature and nothing more. The rate at which they burn in a chamber of a gun can be entirely different.
Click to expand...

Sure. And the powder makers all publish essentially the same caveat, as you just stated, with their charts. Not news. But how else can you get a better quick ballpark ranking of the burn rates?
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I place a great deal of importance in burn rate charts because in a 10,000 ft view they are an accurate representation of the RELATIVE burn rates.
Combined with the CC capacity of your case and the specific gravity of the powder will enable you to find the top 3 or 4 candidates for research in a collection of loading manuals. If you expect them to be exact in all cases you would be wrong. Just changing a bullet weight can reverse the results.

SheepDog said:
I put very little faith in listed powder burn rates. They are accurate representations of the burn rate in a confined space ignited at a specific temperature and nothing more. The rate at which they burn in a chamber of a gun can be entirely different.
Click to expand...
 
ireload2 said:
I place a great deal of importance in burn rate charts because in a 10,000 ft view they are an accurate representation of the RELATIVE burn rates.
Combined with the CC capacity of your case and the specific gravity of the powder will enable you to find the top 3 or 4 candidates for research in a collection of loading manuals. If you expect them to be exact in all cases you would be wrong. Just changing a bullet weight can reverse the results.
Click to expand...

I would agree if the powders being examined all produced the same pressure in the tests. The fact is they don't. In a closed "bomb" test they use the pressure/time curve to compute the relative speed. Comparing 20 grains of Bullseye to 20 grains of H1000 in the same size sphere is totally different than what happens in a gun. Look up the process used in closed bomb tests and you will lose some of that trust in powder burn rate charts.
 
What's wrong with using the QL program in finding which powder that will work the best, in the case/bullet,bbl length etc, etc being tested?

QL works very well, and it's a whole lot better than guessing from the RELATIVE powder burn rates posted via the powder company's.

YMMV,

Tia,
Don
 
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