Powder burn rates

[ol'pole]

I have been looking at powder burn rates from different sources, I've printed charts from 5 different sources plus my reloading manual, compared them and their all different I know that HP-38 & win 231 are the same and H-110 & W296 are also, on some charts they're separated by 2 or 3 different powders and every powder manufacturer has their own charts that list burn rates 5 to 10 spaces differently for the same powder.??
example; #5 on some charts is ranked @ 14th fastest between Green dot and Unique and on other charts it's ranked 39th between Power Pistol and HS-6 and HS-6 and Power Pistol is ranked as the same burn rate on other charts Is there a chart that is done by SAAMI or some other organization that is more reliable than what is available on the web?
I, why isn't there some uniform burn rate test that everybody can follow??
ANY info will be appreciated

[JEBar]

you confusion is well understood and at least with me, understood .... decades ago I made the decision that to find reloading numbers I could have confidence in, I had to find a source for those numbers that chose to believe .... I choose to load Nosler bullets so I follow their recommendations, end of story .... if forced to load a different brand, I use their manufacture's recommendation .... I don't cross check, I don't care what any other source says .... doing so has served me well since the mid '60's .... Nosler list W296 and H110 as being pretty much the same and we use them interchangeably in our hunting level 44 Mags

[ol'pole]

That's good if you load 1 brand of bullets, I load lots of lead of different brands and different calibers. Just trying to find a reliable source, I have load books from all the powder manufacturers that I use and a Lyman manual and of course online

[Rifletom]

Hmm. I'd hazard a guess that the labs doing the testing, Speer, Lyman, Hornady etc, probably had different "lab conditions", whatever that might have been. Powder manufacturers probably keep said information close to the vest. Trying to figure all that out will be something of an adventure. It's why I cross reference powder manuf website data with manuals. Been safe so far, but I don't load hot for anything. Baffling, I know, but, there it is.

[NHshtr]

Powder burn rate charts can drive you insane. Same as Min and Max loads from different manuals. So I follow the same track as JEBar. Which ever bullet is being used, I use that set of load data (Sierra, Hornady, Speer). If I can't find a bullet mfr's load data, I'll try the powder mfg's data (usually online) with the closest bullet. Sometimes the same bullet is found.
If I'm using lead bullets, I use the Lyman Manual loads, which usually cover a decent set of leads to compare.
Sometimes I go rogue, but not often.

[Grunt67]

I do the same. Hornady bullet, Hornady info. Sierra bullet, Sierra info, etc. Served me well since 1967.
Out of curiosity. a few weeks ago, I cross checked the same bullet with different manuals. Huge difference. Would not go there. Travel at your own risk.

[BruniX]

Me too...
first i choose bullet, and after i find reload data for it...
BeuniX

[Oldbrass]

Hornady 9th and Lyman 49th is a good example, there are differences in max charge data across the board probably due to in house testing. If your firearm is in good condition you'll be fine.. Be very careful with antiques like my brothers 1893 mauser ,but that's another story.

[Headhog]

I never paid much attention to powder burn rate charts. Studying a lot of these charts no 2 burn rate tables agree, so I never found any value in them. The majority of the loads I create are from powder manufacturers data and never approach their maximums.

Paul

[Vaquero]

Hmm. I'd hazard a guess that the labs doing the testing, Speer, Lyman, Hornady etc, probably had different "lab conditions", whatever that might have been. Powder manufacturers probably keep said information close to the vest. Trying to figure all that out will be something of an adventure. It's why I cross reference powder manuf website data with manuals. Been safe so far, but I don't load hot for anything. Baffling, I know, but, there it is.

Ditto Tom's answer, with one expectation, my Marlin 308 MX.
It is the only firearm that is loaded to a near max load with either CFE 223 or LVR and 170 gr. JSP's by, Speer or Sierra.
But these loads were worked up, and it is where it is the most accurate.

RP

[Rifletom]

Hmm. I'd hazard a guess that the labs doing the testing, Speer, Lyman, Hornady etc, probably had different "lab conditions", whatever that might have been. Powder manufacturers probably keep said information close to the vest. Trying to figure all that out will be something of an adventure. It's why I cross reference powder manuf website data with manuals. Been safe so far, but I don't load hot for anything. Baffling, I know, but, there it is.

Ditto Tom's answer, with one expectation, my Marlin 308 MX.
It is the only firearm that is loaded to a near max load with either CFE 223 or LVR and 170 gr. JSP's by, Speer or Sierra.
But these loads were worked up, and it is where it is the most accurate.

RP

Yeah, some loads just like being near or at max to perform the best. My 30-30 with W 748 may be my only exception.

[220]

You need to keep in mind that the burn rate of powder batch to batch can and does vary.
It is the reason manufactures recommend reducing loads back to starting levels and working up every time you move to a new batch of powder.

The difference in charts is very easy to understand when you take batch to batch variation into account.
Powders can easily swap position depending on the batches being tested.

[220]

Did a little searching after my previous post as 4% variation rang a bell as the industry standard.
Couldnt find much but a couple of articles did state what I thought I could remember that being 4% is the allowable batch variation for powders.
Still not sure is the 4% is plus/minus from standard or total spread either way it explains most of what has been discussed.