Burn rate charts

[AJC1]

There are tons of burn rate charts around and strangely they dont agree at all. I tend to put a decent amount of faith in my lyman manual chart and the 2019 hogden chart is way out to lunch. Which chart overall do you prefer, an is that based on the powers you use most or some other factor.

 

[Howa 9700]

I've observed the same thing.

The question I have is what objective parameter is used to establish those? Or is it subjective?

 

[MEHavey]

Please folks.... don't use burn-rate charts for anything but "...is it a fast, or is it a slow powder ? ... at the start
Those charts don't tell you anything else.

- Whether it burns faster as pressure rises... or slower
- -- Progressive (or de-gressive) burning rate (with increasing pressure)
---- Progressive burning limit (at which point it quits increasing pressure)
- How much energy is released/grain burned
- Specific heat ratios (specific heat at constant pressure vs the specific heat at constant volume)

Take a look at these two powders -- right next to each other on the "Burn-Rate" Chart.

Loaded in a 357/160gr w/ equal powder weights.



Look at the differences going in to the case, what happens upon ignition, and what comes out of the 5" muzzle. Bottom Line: Burn Rate charts are not a basis for hand-
loading ammunition based on burn rate "similarity"

WARNING: DO NOT USE ANY INFO ABOVE FOR ANY LOAD.
CAUTION: This post includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The HighRoad, nor the staff of the High Road assumes any liability for any damage or injury resulting from the use of this information.

 

[AJC1]

I've observed the same thing.

The question I have is what objective parameter is used to establish those? Or is it subjective?

I believe each company has the testing to rank their own products. Meshing that information is where I think things go sideways. Now that vista owns basically everything it could be fixed rather easy IMO.

 

[AJC1]

Please folks.... don't use burn-rate charts for anything but "...is it a fast, or is it a slow powder ? ... at the start
Those charts don't tell you anything else.

- Whether it burns faster as pressure rises... or slower
- -- Progressive (or de-gressive) burning rate (with increasing pressure)
---- Progressive burning limit (at which point it quits increasing pressure)
- How much energy is released/grain burned
- Specific heat ratios (specific heat at constant pressure vs the specific heat at constant volume)

I use it to help find like powders and true blue was my first experience, where it was waaay off. The ramshot chart showed that clearly and had I believed that chart I would have known blue dot and true blue were no where near the same. True blue is just ever so slightly slower than siholloette.

 

[fxvr5]

True blue is just ever so slightly slower than siholloette.

How were you measuring burn rate of these two powders?

 

[AJC1]

How were you measuring burn rate of these two powders?

Load density. If 8.4 grains siholloette gets me about the same speed at 8.8 grains true blue and the starting load of blue dot is 9.6. I dont have blue dot so I cant test the speed in the same gun but the starting load is higher than eithers max.

 

[cfullgraf]

Burn rate charts are interesting but beyond that I feel they are useless. As noted, different test facilities come up with different ratings. That should tell you something right there.

If I cannot find loading data from a reputable source form a particular powder and cartridge, I figure there is a reason for that and move on to some other combination.

 

[AJC1]

Burn rate charts are interesting but beyond that I feel they are useless. As noted, different test facilities come up with different ratings. That should tell you something right there.

If I cannot find loading data from a reputable source form a particular powder and cartridge, I figure there is a reason for that and move on to some other combination.

I feel like powder can be used for a lot more than what is published. If there is a load for 4198 I believe reloader 7 would also work. Testing every variation would cost an insane amount, and why I believe quickload was created and is a beautiful thing. Some combinations are not a good idea like cfeblack in a 9mm because those questions do come up.

 

[cfullgraf]

Load density. If 8.4 grains siholloette gets me about the same speed at 8.8 grains true blue and the starting load of blue dot is 9.6. I dont have blue dot so I cant test the speed in the same gun but the starting load is higher than eithers max.

This is where a burn rate chart can get you into trouble. Being near by on a burn rate chart does not mean anything that the charge weights will be the same, or near the same for two different powders.

Hence, the need for reputable load data from a reliable source.

 

[MEHavey]

ALCON: See Post#3 for added info/example of "Don't Do It"

 

[AJC1]

This is where a burn rate chart can get you into trouble. Being near by on a burn rate chart does not mean anything that the charge weights will be the same, or near the same for two different powders.

Hence, the need for reputable load data from a reliable source.

Volume should never be derived from a burn rate chart, but comparing volume does give good indication of burn rate/power density. 2400 is definitely slower and less power dense than unique.

 

[Walkalong]

They used "closed bomb" tests for burn rate charts, powders behave differently in different cartridges. Burn rate charts are handy to get you in the ballpark of what similar powders might be usable in the same application.

 

[fxvr5]

Load density. If 8.4 grains siholloette gets me about the same speed at 8.8 grains true blue and the starting load of blue dot is 9.6. I dont have blue dot so I cant test the speed in the same gun but the starting load is higher than eithers max.

Is that an industry standard for measuring burn rate? Can you direct me to that technical resource? I'd like to learn more. Thank you.

 

[CoalCrackerAl]

I agree powders can be used for more that what loads are in the books. I been working with blue dot for out of the box loads. Don't start at some crazy off the wall charge. And work your way up. One load i found accurate with B.D is 10 grains with .223 55 grain bullets. Nice easy shooting load. Im working at different 30 caliber loads too now.

 

[Laphroaig]

I like the Hodgden chart because I mostly use their powders. I like to look at them, but agree that you can't base much off of what they show. One thing I do find interesting is to compare burn rates of "Garand safe" powders. If I got in a pinch and couldn't find 4895, Varget, or 4064 it might direct me to a substitute.

 

[cfullgraf]

I feel like powder can be used for a lot more than what is published. If there is a load for 4198 I believe reloader 7 would also work. Testing every variation would cost an insane amount, and why I believe quickload was created and is a beautiful thing. Some combinations are not a good idea like cfeblack in a 9mm because those questions do come up.

Maybe yes, maybe no. I do not have facilities or equipment to do load testing on my own so I have to rely on someone else. I'm not willing to run into "uncharted" territory.

I'll admit I have not used Quickload, but on the other hand, I'm not sure it is the panacea that some make it out to be without more knowledge of its workings.

For folks that are comfortable with Quickload, that is fine, I'm not at this point.

 

[MEHavey]

One: Quickload's not a panacea, it's a tool. And like many useful tools, you can smash your fingers if not used intelligently.
Two: It's part of a 2-Tool set. The companion is a chronograph.

Either used singly -- You're at the end of the runway in Steamboat Springs, your right hand's on the stick,
left hand on the throttle, a bag over your head and plugs in your ears.
(Look at the terrain around Steam Boat sometime.)



Used together -- with understanding and discipline -- a whole new world opens up.


.

 

[AJC1]

Please folks.... don't use burn-rate charts for anything but "...is it a fast, or is it a slow powder ? ... at the start
Those charts don't tell you anything else.

- Whether it burns faster as pressure rises... or slower
- -- Progressive (or de-gressive) burning rate (with increasing pressure)
---- Progressive burning limit (at which point it quits increasing pressure)
- How much energy is released/grain burned
- Specific heat ratios (specific heat at constant pressure vs the specific heat at constant volume)

Take a look at these two powders -- right next to each other on the "Burn-Rate" Chart.

Loaded in a 357/160gr w/ equal powder weights.

View attachment 1048759

Look at the differences going in to the case, what happens upon ignition, and what comes out of the 5" muzzle. Bottom Line: Burn Rate charts are not a basis for hand-
loading ammunition based on burn rate "similarity"

WARNING: DO NOT USE ANY INFO ABOVE FOR ANY LOAD.
CAUTION: This post includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The HighRoad, nor the staff of the High Road assumes any liability for any damage or injury resulting from the use of this information.

So both exceed sammi 35k limit.... and the vhitavori powder appears faster. If both were set to 35k the faster more power dense powder would take a smaller charge. That same observation can be made with standard load data. None of that is what I use or expect from a burn rate chart. I understand the need to stop people from trying to interpolate data from the chart. I believe using the numbers to check the chart is safe and sane.

 

[MEHavey]

f both were set to 35k the faster more power dense powder would take a smaller charge

The problem being... that a simple Burn Rate extrapolation would have both powders loaded
more or less equally by weight -- potentially disastrously.

'Setting both to 35K' is similarly impossible by referencing Burn Rate chart values.
(You can do it by Quickload/backstopped by chrono readings... but not by Burn Rate charts)

 

[Charlie98]

I like the relative burn rate charts, like the one at Western Powder. What burn rate charts don’t show is how a powder burns. Powders very close on a chart may behave very differently with an identical handload component build. As someone else mentioned, a burn rate chart is a valuable tool, but it’s not the end all, just like a chronograph is not, either… but just very handy tools.

 

[AJC1]

The problem being... that a simple Burn Rate extrapolation would have both powders loaded
more or less equally by weight -- potentially disastrously.

'Setting both to 35K' is similarly impossible by referencing Burn Rate chart values.
(You can do it by Quickload/backstopped by chrono readings... but not by Burn Rate charts)

This idea seems to be reoccurring about using said chart to develop a load.... it was never presented here and has been stated clearly by me to be a terrible idea. Why does it keep being referenced? I did state that data could be be used to validate positions on the chart and setting both to 35k would accomplish that. Interestingly the power density number used in the program will tell you the same thing with no calculations.

 

[MEHavey]

We ain't talkin' `bout you AJ.
Post #1 was just a convenient jumping off point for a " recurrin' subject " that's
a perennial favorite amongst the desperate in these AWOL-powder times....

 

[Grumpy_old_Fart]

Either used singly -- You're at the end of the runway in Steamboat Springs, your right hand's on the stick,
left hand on the throttle, a bag over your head and plugs in your ears.
(Look at the terrain around Steam Boat sometime.)



Used together -- with understanding and discipline -- a whole new world opens up.


.

There's an airstrip at steamboat springs? Oh, wait. You're in Virginia.

 

[joneb]

For pistol powders I put them in three categories fast, medium and slow. For rifle powders I do the same but I realize there is a overlap between the two.
I don't pay much attention to burn rate charts beyond what I said above.