powder burn rate charts

[Dux-R-Us]

There are numerous relative powder rate burn charts published on the WWW. They are all very similar. The charts are qualitative, not quantiative.

I did some searching of opinions on the www to try to find an answer to whether or not these charts mean anything or are useful in their current form.

I came away with the opinion they are not useful, which makes one wonder why they are published. They include flakes, spheres and extruded pellets.

I am curious as to the readership's opinions.

Tally ho!

Kevin

 

[RonAKA]

I have a bit of an issue with the burn rate charts that are just a numbered list -- Hodgdon's is an example. They provide no relative relationship showing how much difference there is between the powders, and which ones are essentially the same.

On the other hand I find the Vihtavuori Chart below to be very useful. It shows how the various powders compare and where there are gaps. They are not useful as a powder substitution reference i.e. 30 grains of this is equal to 30 grains of that. But they are useful in identifying powders of other brands that may work in your cartridge. They also keep in perspective whether you are going slower or faster with your choices.

 

[TheSnake]

RonAKA
Do you have your chart is a larger version? My eyes are not what they used to be. :'( Thanks!

 

[tunered]

Go to this site and download [ on right side of page] and get the manual, that powder chart is one of the first pages in the manual. ed

http://www.lapua.com/index.php?id=847

 

[RonAKA]

RonAKA
Do you have your chart is a larger version? My eyes are not what they used to be. :'( Thanks!

Mine aren't so good either at 60+ years. For some reason this site scrunches the chart down. At least on my computer this one shows larger, and works with my bifocals!

http://www.lapua.com/fileadmin/user_upload/Relodata/Burning_Rate_Chart.jpg

 

[Dux-R-Us]

They also keep in perspective whether you are going slower or faster with your choices.

Okay, this is what I am getting after. The chart will allow you to know whether you are changing to a RELATIVELY faster or slower burning powder. When developing a load, are there indications (and if so define them) that a signficantly slower or faster burning powder would be warranted? Or is it still trial and error?

Here is an example, which just might be coincidence, because I did not consult buring rate charts when developing this load, and my degrees of feedom in this analysis are quite low (d.f.=0). I tried 3 different IMR powders in .308 Win. to shoot in my M77 International with 18.5" barrel. Of them IMR 3031 grouped the best. IMR 3031 is relatively faster than the others I tried (IMR 4350 and IMR 4064). Or this simply arm waving? Or is it the dram of Jameson effecting my brain??

If you know a Veteran, thank he or she tomorrow.

Here is my sincere "Thank you" to all the Veterans that read this post. I truly am gratelul for those that chose to or were called to do that job, and did it.

Tally ho!

Kevin

 

[necchi]

"Or is it still trial and error? "

Generally, larger bullets /slower powder--Smaller/Faster,,Right?

I think if you spend any time reading "How too," loading books by several gents and forums filled with many opinions,, you'll see a trend where people will find a favored powder or 3 that they like, then spend lots of time promoting said powder(s) to others.

The big deal is there are so many variables each person can mess with to perfect a load, that in fact several powders can and do work well across any given range,,There Is No Definitive Answer.

Every load book out there lists several powders from fast to slow for any given bullet and cal/case?? So in effect it IS still trial and error useing YOUR techniques.

I'm not a pro,,that's just my take on it. IF there was a single best answer why are there so many different powders winning matches?

Differnt guns, different barrels???