relative powder burn rate charts

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oldscot3

New member
Recently some new powders have hit the shelves and I've purchased a couple of them so I went to work updating the burn rate chart I have near my reloading bench. The charts in my manuals are rather old ( 7 or 8 years ) so I hit the net. I found a good recent chart, that lists all the new powders, and was a little surprised to see it place IMR-4350 two numbers slower than H-4350. Every other chart I can remember lists IMR-4350 as slightly faster.

I wonder if that's a mistake, or if recently manufactured lots of one or both of those powders has changed to the degree that it warrants a change in their position on burn rate charts? Anyone have an inside scoop?
 
No, no inside scoop but just a comment on burn rate charts that are distributed by various sources and unknown if each source gets its data from the same pool of information, or from their own seperate data sources, and that from over 100 different powders how each distributor could be expected to all be in absolute agreement. So what shows in one chart could be slightly different than what appears in another chart. Perhaps that is why the 4350s (or others) don't exactly line up in various charts.
 
What really piqued my interest about it, was a separate (possibly related) issue with regard to Hornaday factory ammo for the 6.5 Creedmoor. Their 140 grain A-Max load, of months past, has apparently had some reports of overload issues. The load recipe that was printed on the box was for H4350. While that doesn't mean it necessarily was H4350 in the loads, Internet rumors suggested they had problems with the Hodgdon powder and switched to Reloder 17.

If any of that is true, then perhaps newer lots of H4350 is quicker burning than it was in the past.
 
There is virtually no consistency in burn rate charts I have charts that put HP38 five or six steps up or down from 231, and they have always been the exact same powder.
True Blue can be nearly as slow as long shot or faster than aa5 depending on chart.
Relative is a very loose term.
 
Accurate, Western powders and Ramshot has the best online burn rate chart that I've seen.
Powders of about the same burn rate are shown on one line regardless of brand.
 
I was looking at mixers in an apartment store, and I noticed the different brands had a different hierarchy for chop, mix and whirl.

Worse, reading recipes [on chocolate chip bags] I found huge discrepancies in the amount of egg added.

As a professional, I try to keep MY lies consistent.
 
Burn rate charts

BURN RATE CHARTS
I do like to look at them.
But, that is the only thing they are good for.
They prove nothing, differ, and are not a substitute for load data.
 
All they are good for is to tell you that 4831 is slower burning than 4350 and 4198 is slower than Bullseye. You have to go to the manufactures load data to get load info.
 
Take them with a grain of salt. It's no different than looking in reloading manuals and seeing two different loads for similar powders such as H110/W286 and W231/HP38. SMH
 
I highlight, or otherwise indicate, which powders I have on hand, then when I'm perusing load data I can know If I have the ingredients for a certain recipe or if I need to look for data for a nearby( burn rate ) substitute.

When taking on a new cartridge, referring to a burn rate chart shows the strength or weakness of my powder inventory for that cartridge. For example, currently I have little in between slow pistol, such as W296 and medium rifle such as IMR 4064. If I start loading for a cartridge such as 7.62 x 39 I may have to address that situation and I can see a number of powders on the chart that may be suitable to purchase.

Most experienced loaders know seemingly small factors, such as different primers or different brands of brass can have an effect on pressure and therefore should always consult reliable published load data for their specific ingredients. But if you never consult a burn rate chart, you're missing out on a handy information tool.
 
I highlight, or otherwise indicate, which powders I have on hand,
Click to expand...
Yes, and then I collect the load data for the calibers I load, and powders I have on hand.
I use Load Data, and only load data, to identify powders I should add.

The relative burn rate is irrelevant, when I am looking for new loads I want. What is relevant is the proven load data, for powder X giving 3,600 fps when powder Y only gives 3,400 fps.

A powder may look good based on a burn rate chart, but might have no data for what I want to load. Ultimately burn rate charts, by themselves mean nothing.

You may see a correlation between burn rates per charts and powders for which data exists. But again, this does not prove that the powder will work in your parameters. You must defer to load data.
 
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