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Powder burning rates?
litetrigger
Member Posts: 319 ✭✭
Anyone know where I can get a chart of powder burning rates? thanks
Comments
I hope that works for you.
This is the one I worked on:
http://reloadersnest.com/burnrates.asp
Best.
1. The same powder burned in different cartridges can exhibit a wholly different burn rate, which can be different than it did in the lab tests.
2. In any "One through xxx" list, two adjacent powders can be identical or miles apart. There is no way to know how much slower or faster any two powders are.
In other words, such lists are nearly useless for load determination.
Just remember two things about burn rate charts:
1. The same powder burned in different cartridges can exhibit a wholly different burn rate, which can be different than it did in the lab tests.
2. In any "One through xxx" list, two adjacent powders can be identical or miles apart. There is no way to know how much slower or faster any two powders are.
In other words, such lists are nearly useless for load determination.
Rocky,
I have to disagree with your last statement. Although powders do exhibit different burn rates in different calibers one can determine a decent load through interpolation of burn rate. But, one must also know the pressure rating and properties of a given powder. Meaning two powders burning the same speed are not going to give the same pressure. You find this difference most notable in single and double based powders. You will also find it with coated, mixed, and uncoated powders.
Moving up and down a given brand/manufacturer isn't difficult at all. Meaning if I had a round that started with RE-15 but I wanted to change to a heavier bullet and needed to keep that speed then I would move to either RE-17 or Re-19. Same with Vihtavuori.
Where it gets dicey is when moving from say IMR powders, which for the most part are uncoated, and VV powders which are not heavily coated but use cotton as their cellulose structure instead of wood like IMR. In most cases this wasn't a difficult task. Except in the WSM/WSSM cases. There were some close calls of interpolating then reducing load and still coming out at max. I also found this to be true in some of my Ackley cases.
So, if you are trying to find a load with a powder you don't find in a book, the best way to do it is find a powder of the same type/brand. Compare that in speed to the one you want to use. Reduce to absolute minimum. Then work up. Those load interpolations, you will find, give more consistency in speed/pressure than anything else.
IF YOU EVER HAVE A QUESTION ABOUT A LOAD, CALL THE POWDER MANUFACTURER! They can give you a good starting load, or tell you not to use that powder.
Good luck and BTW, most reloading books have powder relative burn rate charts in the front or in back in the reference section.
Within a given brand, your points are valid, provided the company ranks their own products by burn rate and applicability.