Powder Comparisons

IMagius

IMagius

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First: I tried searching, but either I don't know what to ask the search engine (keywords) to get the answers I want, or I missed a valid result. (Yes, I know about changing the default setting in the seaarch option to 3 years)

My question:

For years, I've followed the various books from various suppliers when making up new loads. Hodgsons, Speers, Hornady, etc.. Each book will list a variety of powders and measures for any given bullet choice.

Over the years, from time to time, I've developed a load that someone has told me "You shoudl use a slower/faster powder than that." Obviously, since the load was well within range in the books, and was shooting safely, it was fine and somethign I chalked up to "personal choice" on their part. And I recognize and try to follow the age old rule of "slower powder for heavier bullets" while trying to maintain 98% case capacity.

What I really want to know is ... Is there, somewhere, a comprehensive list of all the (common) powders and their comparative burn rates?

I can look at the loads given for a specific round and guess based on the recommended measures that IMR 3031 will be more/less than the next powder listed in the chart, but that's not much of a help to me.

Is there a way to look up the rate for IMR3031, compare that to say IMR4198, and then compare both of those to something like Varget? A website maybe? Or a specific book that delves into such things with specifics?

I've tired going to some of the websites (like the Hodgson's site in the sticky at the top of this forum) but most seem to just show the recommended loads, not any specific details on the actual powders.
 
Burning rates of powders are established in spherical (bombs) expansion chambers. While in cartridges they display relative orders as well in terms of time-pressure curves, these may be quite different from the bomb rates and can also vary from one cartridge to another. So, one powder that is "slower" than another in one cartridge may be reversed in another depending on the volumetric ratios of case capacity to bore diameter, bullet mass and even primer type. This is why is virtually impossible to see a relative burning rate chart for cartridges. Nevertheless, some approximations can be made from one cartridge to another as to which powder can behave like another.
 
'Boo said:
Every reloading manual I have ever seen has the tables you are looking for.
Click to expand...

Yes, but I haven't seens an "industry wide" chart. Maybe I need newer books again :(

Miltiades said:
Burning rates of powders are established in spherical (bombs) expansion chambers. While in cartridges they display relative orders as well in terms of time-pressure curves, these may be quite different from the bomb rates and can also vary from one cartridge to another. So, one powder that is "slower" than another in one cartridge may be reversed in another depending on the volumetric ratios of case capacity to bore diameter, bullet mass and even primer type. This is why is virtually impossible to see a relative burning rate chart for cartridges. Nevertheless, some approximations can be made from one cartridge to another as to which powder can behave like another.
Click to expand...

Hence my question ... While necked shells should act similarly, I could certainly see there being differences in the reactions of the same powder when compared to a straight shell casing ... pressure waves do odd thigns at times :/

kombayotch said:
Try doing a search for: "burn rate chart"... you end up getting a lot of results that look like this page: http://www.hodgdon.com/burn-rate.html

Every powder manufacturer has one on their page.
Click to expand...

Thanks for the link :) I've seen that chart (and simliar) before and it has the basic listing, but no "data" to go with it. ie: IMR4198 is a 71, and IMR3031 is a 78 ... but what's that mean? How much faster is the 4198? 1% ... 5% ... 0.5% ???

Honestly I don't even know what data I am looking for ... I just want to learn more about how each powder works and why. It's more of a thought experiment for me to learn more about the powders I am using ... I don't like just "painting by numbers" when I'm making new loads and would like to understand more about what is a key element in a handload.
 
While I understand and appreciate your need to review such a comprehensive list, unfortunately the only way to obtain what you really seek is to try the loads in your rifle, as you are certainly aware.

Years ago Higginson's used to offer a sample pack of powder: you could buy four 1/2 pound samples of various powders (which was fantastic) to see what would work best for you in your particular rifle. I have not seen it listed for several years unfortunately so I think that is no longer available.

Another option would be to seek the advice of reloaders using their rifle in similar situations as you: ie bench rest, LR or just hunting and see what worked for them. As you mentioned a lot may very well be personal preference but some will certailnly be able to shed valuable insight and maybe even cut down on the cost of broadrange load development.

Regards,
 
Thanks for the efforts guys (and gals?), but I'm not seeing the data i was hoping to find in those charts you have kindly provided.

Having given it more thought, in order to explain what I am looking for ... What I want to see is the "burn time" and expansion volumes for each powder - for a given measure. ie: All powders in a chart like those shown, but with two more columns - "_x_ milliseconds to consume n Grains of powder" and "creates _x_ cubic inches expansion with n Grains of powder".

Maybe I'm looking for something that's an "industry secret" ...

I don't "need" this info. Having a selection of various powders and try them all out is why I love reloading. Having a dozen or more "5 round sets" of each powder & various measures all loaded up and ready to put on paper IS my idea of a good time. Even after I have found a recipe that works great, I still love to tinker and see if a different powder will do something else.

For me, it's a question of WHY a certain measure of whichever powder works best or better than another one. Maybe I'm just a data geek :p I hate not knowing why/how something works.
 
Yup, the info you want will just confuse you. To much information can be a bad thing, it will make you second guess your choices of components. Next thing you know the black helos will be watching, Go shoot your reloads and have fun.:D
 
The data you seem to be seeking changes every time the factories get a new load of powder and they must test and compensate for. There is no concrete data concerning a given powder's expansion rate etc. There are industry standards for pressure in a given cartridge, and they will adjust the powder to reach that standard. There used to be a series on powders in the Wolfe Handloader books (they even released a collection of the articles at one time, you should be able to find a copy). This gives you a lot more info on all the powders, though it's dated and a lot of the new powders aren't in there. FWIW - dan
 
IMagius said:
Thanks for the efforts guys (and gals?), but I'm not seeing the data i was hoping to find in those charts you have kindly provided.

Having given it more thought, in order to explain what I am looking for ... What I want to see is the "burn time" and expansion volumes for each powder - for a given measure. ie: All powders in a chart like those shown, but with two more columns - "_x_ milliseconds to consume n Grains of powder" and "creates _x_ cubic inches expansion with n Grains of powder".

Maybe I'm looking for something that's an "industry secret" ...
Click to expand...

Not going to happen! The rate at which the gas expands is highly dependent on the pressure it is burning under, which is not only changes depending on caliber, but will also vary based on chamber dimensions, brand of case (internal volume differences), barrel tightness, primer, etc... Determining that is mathematically intensive. You aren't going to get that info from a chart. Further, just because you put X amount of powder in doesn't mean that it's going to burn completely. A faster burning powder requires a shorter length of barrel for a complete burn than a slower one (all things being equal).

The best solution is to get a copy of Quickload. You input specifics about your barrel, case, bullet, etc... It does what you are trying to do. It runs all of those calculations for all of the powders in it's database and shows you the theoretical, calculated pressures and velocities that each powder will give you.

http://www.neconos.com/details3.htm
 
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