Slower Burning Powders ranked numerically by burn rate

[Veteran]

As some of you may know from prior posts, I like to rank powder burn rates by number
rankings numerically. I hate the charts.

Here's some of the rifle powders that are slower burning.

They are ranked by BA factor.

Lower Burn Rates
RL 22		0.386​
ACC 4350		0.381​
IMR 7828		0.3841​
RL25		0.384​
N560		0.371​
H1000		0.366​
Ramshot Mag	0.345​
RL26		0.3397​
Acc Magpro	0.3342​
Retumbo		0.337​
N565		0.3109​
IMR8133		0.3​
N568		0.3​
Ramshot LRT	0.285​
N570		0.277​
RL33		0.267​
US 869		0.2735​
RL 50		0.217​

 

[RB II]

Here is a chart, for those who don't hate them!!! Sorry, couldn't help it.

 

[8x68s]

sorry, what is BA factor?

 

[Veteran]

sorry, what is BA factor?

initial burn rate starting point for the burn rate curve in an internal ballistics model.

 

[Veteran]

Here is a chart, for those who don't hate them!!! Sorry, couldn't help it.

The problem I have w charts is that I have seen some powders in different places on some of them than on the other, and they can be hard to read depending
on which one, and sometimes they dont have newer powders,
and besides that I just dont like em. Having the numbers ranking, gives me a better perspective in how close a given powder is to another for instance to realize N568 and IMR 8133 have exactly the same burn rate, ( though they may shoot a little differently or the curve of burn rate w time and pressure may behave differently, they are very very close. My velocities should be close too for given charge weight. It just gives me more precise info and more confidence in my goals to view the info this way. The chart is fuzzy relativity to me.

 

[Laelkhunter]

Thanks RB II for posting that. I remember when Bullseye and Red Dot were the fastest powders, now Bullseye doesn't even make the top 10.

 

[sedancowboy]

I notice that RL-26 is slower than H-1000 on the BA factor chart and is faster on the colored chart.
Can we find out what the BA factor is for Stayball HD?

 

[Veteran]

Staball HD is a new powder.....

You forced me to order the update disk for my program.....

So, I will answer this when I get the update.

Its probably between RL26 and N570 though.....my guess.

 

[Veteran]

Staball HD is a new powder.....

You forced me to order the update disk for my program.....

So, I will answer this when I get the update.

Its probably between RL26 and N570 though.....my guess

 

[Veteran]

Other than the relationship of RL26 and H1000, another one that is reversed from the chart is N560 and RL25 I notice. I go by the numbers......

 

[buckbrush]

What does each column represent?

 

[Veteran]

On my spreadsheet excerpt pasted in, left column is the name of the powder, and all numbers to the right no matter what column are the BA or burn rate coefficients or factors for each powder. The whole purpose is to rank powders by how fast they explode and burn. There are some columns that are out of alignment (should be all far right justified) but the wonderful paste function lets them migrate to the left. Gripe---this website will not let you post actual excel or other worksheets as attachments. Afraid of macros, I guess.....???

 

[4thefunofit]

What number tells us how much gas is expelled during a given amount of time? Seems to me burn rate alone doesn't tell us how fast a given powder will push a bullet out the barrel.

 

[Veteran]

What number tells us how much gas is expelled during a given amount of time? Seems to me burn rate alone doesn't tell us how fast a given powder will push a bullet out the barrel.

You are very correct in some regards......The only way to get a velocity which is a proxy for gas push from the explosion in the chamber is to model the whole system. That means length of your bbl. Your caliber, what weight bullet you are shooting,
and the size of your chamber, freebore, AI , etc. Also, your bullet seating depth and coal.
Those physics are what make an internal balistics model like GRT or Quickload.

But as a starting point ,if all you want to know is for my rifle system, which is a constant , what powder can get me a higher velocity without exceeding safe pressure in a relative sense , which is a slower burning powder with more gradual gas expansion and pressure, then the starting point on the burn rate curve is a good relative comparator. Thats the BA factor.