A useful burn rate chart

[Jim]

RELOADBENCH.COM has a nice function on their burn rate. Just above the top of the chart is a list of the powder manufacturers. If you left click on the mfg'r. of your choice, a window will pop up with all the powders mfgr'd. by that company in bold.

I like Alliant brand powders. Using this function, I can easily compare burn rates because only those made by Alliant are bolded. Sure makes it easier to pick them out.

[Rocky Raab]

Once again, may I point out the serious flaw of any such "one through whatever" chart?

Note #71 and #72 are H110 and W296, which are the exact same powder. So how is one faster? Now see #131 and #133, which are W760 and H414. Again that is the exact same powder, yet there is another powder ranked BETWEEN them? How is THAT possible?

Two powders adjacent in number might be identical, very close in burn rate, or differ quite a lot. How do we know? We can't. The chart therefore can't be safely used to determine substitute powders for a given use.

Such charts may serve as a list of available powders, but that's just about all.

[btroj]

Rocky is dead on. It is a neat reference but really has no use on reloading.
I look at the medium speed rifle powders and am amazed at how much the max charges change.
Look at RE15, Vaeget, 4064, BLc2, H355, win 748 and tell me from load data which is the slowest or fastest? Depends much upon the specific load components.

[zomby woof]

Once again, may I point out the serious flaw of any such "one through whatever" chart?

Note #71 and #72 are H110 and W296, which are the exact same powder. So how is one faster? Now see #131 and #133, which are W760 and H414. Again that is the exact same powder, yet there is another powder ranked BETWEEN them? How is THAT possible?

Two powders adjacent in number might be identical, very close in burn rate, or differ quite a lot. How do we know? We can't. The chart therefore can't be safely used to determine substitute powders for a given use.

Such charts may serve as a list of available powders, but that's just about all.

*** This is the approximate order of burning rates for established brands of powder from fastest to slowest. Powders tend to switch positions especially those close in burning rate, depending upon the characteristics of the cartridge and other variables. Be sure to refer to manufacturer loading data manuals for proper charges.

[btroj]

If we are looking at manufacturer or other loading manuals for data what purpose does a burn rate chart have?
Besides being "neat" to look at it has as much usefulness in actual loadi as a bullet board does in selecting a projectile.

[Springfield]

Sometimes there ISN'T a factory loading chart for some calibers. When I was looking for a good load for my 9mm Action Express 15 years ago the chart helped me get close. After that it was all about load development. Took me 5 powders until I found one that would work for me. Sometimes close is good enough, but I certainly wouldn't switch powders straight across without some development. Having factory loads is good but there certainly is still room for experimentation and extrapolation. If not, why are we here on this sight?

[oneokie]

If we are looking at manufacturer or other loading manuals for data what purpose does a burn rate chart have?
Besides being "neat" to look at it has as much usefulness in actual loadi as a bullet board does in selecting a projectile.

I for one like a burn rate chart because there are some instances where published load data does not give the accuracy one desires. By being able to select a different powder with a slightly different burn rate-thus a different pressure curve, I have been able to find an accurate load for a particular cartridge.

[Rocky Raab]

Ahh, that may be true, oneokie; but as noted, how do you know what "slightly different" is? As I said earlier, adjacent listings may be identical, a tiny bit different or quite different - even if burn rate didn't change in different cartridges/circumstances.

There are several "spreadsheet" style burn charts that are much better. In those, each row is a different burn rate. Identical powders from different makers can occupy that same line. THIS ONE from ADI is one example. Again, however, there is no set and consistent "step" between each line. So we still can't tell how much the burn rate changes from line to line.

[btroj]

You, my freind, are far more brave that I. I don't tend to create load data on my own, I prefer something at least somewhat proven.
Promoting the idea that we can use a burn rate chart this way is going to get someone killed. I tend to prefer to err on the side of safety.
They make for interesting reading but have little use beyond that to me.

[azrednek]

Years ago, mid to late 70's. I found a burn rate chart very useful. I had landed a super deal on some Norma brand powders. Once it was gone and Norma powder no longer available through normal channels at a reasonable price. I used a burn rate chart to find powders with a similar burn rate. Let me emphasize that I didn't substitute the numbers. Same as I did with the Norma powder. Worked my way up to max then back down to find the best shot to shot accuracy. I was shooting hi-velocity numbers such as 22/250/ 270 and 308 Norma Mag. If I lost some FPS it wasn't a big deal as the bullets were moving plenty fast.

Back in the 70's cronys were priced beyond my reach. I had to rely on published velocity charts. Once I achieved an accurate load with similar published velocity I was satisfied. If not for having a burn rate chart. It would have likely been considerably more experiments finding a load that in at least my own mind was as good as previously with the Norma powder.

[Rocky Raab]

It still seems like a friendly and useful discussion to me, Jim.

[Dan Cash]

It still seems like a friendly and useful discussion to me, Jim.

With your first post, it turned into an "I am right and you are stupid/dangerous/incompetent" non discussion. Jim never suggested that any one use a burn rate chart to replace proven data.

Just my opinion; your mileage will surely vary.

[btroj]

I didn't see Rocky's post that way at all. Mi saw it more as a "be careful what you do with this info" comment.
We have a huge number of newbies here, they may take the burn rate info and run with it. How safe is too safe?
I think it is a useful discussion.
Is is an area where a guy with ALOT of experience and some common sense can extrapolate safely. A newbie could get in deep trouble in a big darn hurry with the same info.

How cautious is too cautious?

[Newtire]

I notice something every winter on this site. Seems alot of times, reasonable people get really touchy about certain subjects. I attribute it to cabin fever.

I do a little extrapolating myself but usually after looking at results others have had and more than one other usually. "Newbies" are all of us the first time we try a load out.

[frnkeore]

"Note #71 and #72 are H110 and W296, which are the exact same powder. So how is one faster? Now see #131 and #133, which are W760 and H414. Again that is the exact same powder, yet there is another powder ranked BETWEEN them? How is THAT possible?"

Yes, that is the case now but not untill Hodgdon took over the rights. There is still a lot of the pre Hodgdon Winchester powder out there.

I've been useing H414 since 1969 and Winchester 296 since 1987. Winchester 760 is NOT the same as H414 prior to a few years go! I still have Winchester 296, if you'll check out loading data for 296 and H110 from years past, you'll find that they can ONLY be called similuar. Same with H414 and Win 760.

I just bought 2 round steel cans of Win 760 at the last gun show that I went to and I will use it based on 760 loading data not, H414.

I can't say that it's dangerous to interchange data but, I can say that you could surely loosen a primer pocket and have to pull the other rounds or loose the brass.

There is a big question regarding IMR4227 also. Is it 4227 or H4227? I believe that Hodgdon needs to come out and tell the public what it's doing with the powders!!!

So, yes, there still needs to be those burn charts that have them seperate untill Hodgdon 'fesses up.

Frank

[nanuk]

Where I found the burn rate charts useful was when powder supply was very limited, it gave me a chance to see where the powder that was available, fit into the burn rates, then I could research out load data, through manuals et al to find loads that were appropriate.

if I could not find load data on a specific powder, then I compared the load data from it to other common ones that are near it, in similar sized cases and then searched more for the more specific loads....

I have noticed that some powders have starting and max loads very similar in ratio, throughout several cartridge cases.

I would not hesitate to research a load, and if it looked reasonable, start at a lower end, and work up.

sometimes, this is all we have to get our guns shooting.

Common sense can play a role in development.

[btroj]

Common sense MUsT play a role in load development. Problem is that a burn rate chart in the hands of someone who doesn't Use common sense is dangerous.

I basically do as you are describing but I don't look on a burn rate chart. I go thru numerous manuals looking at the cartridge and bullet I plan to use and see what powders can get me where I want to be.

These charts are neat information. It they are no more than an approximation. Look at how many of the charts have differences in locations of the powders?

I just want the charts to be used as intended, for information only. They are not for load development.

[Shiloh]

Once again, may I point out the serious flaw of any such "one through whatever" chart?

Note #71 and #72 are H110 and W296, which are the exact same powder. So how is one faster? Now see #131 and #133, which are W760 and H414. Again that is the exact same powder, yet there is another powder ranked BETWEEN them? How is THAT possible?

Two powders adjacent in number might be identical, very close in burn rate, or differ quite a lot. How do we know? We can't. The chart therefore can't be safely used to determine substitute powders for a given use.

Such charts may serve as a list of available powders, but that's just about all.

This post asks the same questions I have asked myself and others many times. How can the same powder with different names have different rates??

Burn rate charts are guides only. Use reloading data for a particular powder from that powders manufacturer.

WHen looking at printed or online burn rate charts, and there are many, one will notice that they are all different. Some will list a particular powder ahead of others in one chart, and the exact opposite in another.

Shiloh

[para45lda]

And please don't mistake post count with experience.

[Rocky Raab]

I regret if anyone thinks I'm being confrontational or overbearing. It is not my intent. (And thanks for unlocking it again, mods.)

Let me summarize my opinion on burn rate charts before I turn to other tangential points raised in this thread: Burn rate charts are interesting and can provide useful information. No two are alike, and some are much better than others in both the veracity of the data and the manner in which it is presented. None of them should be used to interpolate or extrapolate actual load data. That about sums it up.

frnkeore, may I politely disagree? From the beginning, there have been many H/W pairings of the exact same powder. Those include HP-38/W231, H110/W296, HS-6/W540, HS-7/W571, and H414/W760. It was and still is usual for an entire run (lot) to be packaged as one or the other, however. That can lead to variations as large are 5%, but not normally more than 3% in key characteristics like burn rate. So it is possible for a can of "H" to perform differently than a can of "W" even though they are the same powder made to the same recipe. That has never changed. My source for the above is Chris Hodgdon, by the way.

The 4227 issue is moot, because Hodgdon has discontinued production of H4227.