Gun Powder

[Kevin Stenberg]

A lot is written about the different gun powders and the speed and the amount of gas they produce. I know about the burn rate charts that show the relative speed of one powder to another. But they fall short on information of how fast any specific powder burns at. Honestly I have never looked on any powder container, or asked any manufacturer for any such information.
So where can I go to find information so I can see the differences of powder A to powder B.
This is what you guys get when trying to teach us cavemen on new ideas. Questions Questions Questions .Before I started casting and learning from the old site and here. I wouldn't even have considered it important to know Burn Rates - Alloy content - Bore size Yada Yada Yada. See the monster you have made. THANKS. It was so much easier when I was happy that the bullet came out the muzzle of my firearm and hit the target. Kevin

 

[JSH]

I have never seen two burn rate charts the same from different sources.
I myself have 2-4 that I use, then just as a small reference.

Different bore sizes will also influence how powders act.

 

[Rick]

Kevin what you ask for would be nearly impossible to put into a chart. Numerous factors influence any powders burn rate and sometimes considerably so. Case capacity, bore dimensions, bullet weight, ambient temperature, humidity are only a very few. Change any of them and the burn rate is changed for the same lot of powder. The first and most important thing to learn is that burn rate charts are not loading guides and should never be used as such. The reason most published burn rates differ is that the testing is done by different methods and with different equipment by different people which all effect the burn rate.

Burn rate charts are a mere guide, they are but one additional piece of the puzzle and should never be considered any more than that.

 

[fiver]

probably the best way to figure it out is to stick with one Brand of powder.
then after a bit your familiar enough with them to really see that even though they are listed in a 1-2-3 type order some times 3 act more like 4 and sometimes it acts more like 2.

what happens is the initial engraving spike pushes it a little higher in one instance and sometimes the container it is in speeds up the burn rate.
it becomes pretty predictable in each instance but you have to try it for yourself to see that.

trying to look at some of those overall or comparison charts confuses the hell out of me, because I know some powders do not fall where they put them, and quite often the whole line of brand C. is 2 places too low.

how I approached it when I forst got interested in powders was to break them down into groups.
[...........................................] [......................................]
the first group is your red-dot window from Alliant.
finding the ones from the other manufacturers that would go in that group was a bit more difficult, many of them had been discontinued, Alcan-120, royal scot-D etc. but you still have clay's and 700-X.

then you have stuff similar to bulls-eye such as 231.
it burns well enough at 3.5 grs but can be stretched out to 7grs in many cases.
sometimes it is in speed #1 sometimes it is in speed #2.

then the next speed window.
green-dot, international clay's, P/B
and so on down the line.

once you have a better visual of groups of powders instead of actual [#48-49] burn rates, you can see what each group should be doing at a similar volume and pressure window.
that will help you predict a switch between them when your looking for whatever you can get during a shortage or when your trying to go faster while keeping the same pressure.

 

[358156 hp]

Powder burning rates are tested in a sealed chamber, referred to as a "bomb", where the powder sample is ignited, and it speed of burning and the internal pressure (& pressure curve) inside the bomb is recorded, then analyzed to derive the information needed. The real problem here is that the bombs all have the same internal capacity +/- tolerances. When we burn powder in a cartridge, there are huge variations in capacity, case design (& manufacture), bore size, ignition source, environmental conditions, and well, you get the idea. It amazes me that the whole process works as well as it actually seems to. This sort of thing could initiate conversations and positions that we, as handloaders, cannot prove or disprove with the resources we have available to us. We rely on our own experiences, and on the experiences of others, hopefully guys like we have here with huge amounts of experience. Published "burning rate" charges are rough guides at best, loose categories might be a better term.

 

[S Mac]

I am trying to get a better grasp on the different powder uses and suitabilities, for example a load for two different rifles, same cartridge, one with a longer barrel utilizing a slower powder more efficiently. Is that a correct assumption? With possibly better accuracy?

 

[Rick]

Well yeah, more what I do is use the slowest powder with a heavy for caliber bullet that will get me to my velocity goal. Even tried 1680 in the 357m and almost got there, shot pretty well too.

 

[JonB]

I have never seen two burn rate charts the same from different sources.
I myself have 2-4 that I use, then just as a small reference.

Different bore sizes will also influence how powders act.

Yes, I agree...I use 3 or 4 of them.

I'll add that I found one. It is in a slightly different format, I really like it.
http://gsgroup.co.za/burnrates.html
But I should add, this one is surely not perfect (look at W296 in comparison with H110...they aren't on the same line, in fact they have them placed two lines apart, LOL). So when looking at this, be sure to compare it with others.

Also, the Powder Chapter in "Nick Harvey's Practical Reloading Manual" has a multipage powder burn list of sorts, He groups them like Fiver describes, and for each powder he explains what the powder is best for (in his opinion)...problem is, his info is a bit dated and the list isn't very long...like about 30 powders...and He is Australian, so there's that, LOL. Anyway, I highly recommend this book, it's not a "company" produced book, it's a book one man put together from his vast experiences...he generated his own data. It's great to have his data to compare to, when researching a new load.

 

[358156 hp]

Well yeah, more what I do is use the slowest powder with a heavy for caliber bullet that will get me to my velocity goal. Even tried 1680 in the 357m and almost got there, shot pretty well too.

I was ready to try IMR 4198 in 44 mag with 300 gr cast at one point to test John Ross' recommendation for myself, but never followed up on it. My real life got topsy turvey, and I couldn't focus on the project, and it fell by the wayside. I just went looking for that article, guess where I found it? http://www.lasc.us/RossLoadingthe44magnum.htm

 

[Rick]

IMR 4198 works quite well in the 454 for a reduced load. 240 gr bullet at 1430 fps and shoots quite well. A real PITA to load though, to get enough in the case and still be able to seat a bullet ya need a drop tube.

 

[4060MAY]

National Center for Forensic Sciences, if you can decipher the information

http://www.ilrc.ucf.edu/powders/sample_detail.php?powder_id=18

 

[Ian]

Bottom line question:

So where can I go to find information so I can see the differences of powder A to powder B.

Bottom line answer:

We rely on our own experiences, and on the experiences of others, hopefully guys like we have here with huge amounts of experience. Published "burning rate" charges are rough guides at best, loose categories might be a better term.

....for all the excellent reasons everyone listed about "it depends on....".

You just have to start branching out with the "What does it DO?" mindset, starting with published data and then changing this or that to see what happens. A chronograph is the only affordable tool for most of us that gives an indication of changes. This is how you figure out that Titegroup is a flash-bang akin to Clays and that Bullseye behaves more like Universal than Unique does. Red Dot is flashier than BE, very spikey burn curve pretty much in any case or expansion ratio, but Titegroup is much more predictable and gentle in a big case with a small bore. Look at a burn rate chart compared to what I wrote and see that things don't always stack up due to "depends".

Here are a few that I have put in a pretty firm row, in pretty much any application that's appropriate for them, in order from fast to slow: Unique, Herco, HS-6, Longshot, True Blue, and 2400.

 

[freebullet]

Burn charts are just another reference, can be helpful for comparison, & when loading off the reservation.

 

[Kevin Stenberg]

I guess I wasn't to far off of track with how I used burn rate charts. Which are to be used as a reference in picking similarities.

 

[Rally Hess]

Burn charts are just another reference, can be helpful for comparison, & when loading off the reservation.

That's funny, and true!

Ian,
Shouldn't that list start with BE? or 231?

Interesting how much powder research has been on the websites since the "powder shortage" came and went. Seems a lot of us were pretty loyal to a few powders, then had to check out what was available.

 

[fiver]

most think BE is the fastest powder but it isn't.
it is fast of course but it will extend out past almost all of the other fast powders in the amount you can use on the top end.
in my 357 I use 6 grs of it under a 148 wad cutter, and could probably go to 6.5 or 7.
that's right where unique would pressure out, and is middle back with Herco.
there is no way either of them would work down at the 2,7 gr area that bulls-eye would with the same components.
so while it burns pretty fast it also has an extended top of the pressure zone where it doesn't keep climbing.
other fast powders peak quickly also, but if you add more they just keep climbing until they burn all of the powder.
kind of like a fire that gets so hot it starts igniting stuff around it without touching it with any flames.

 

[Ian]

Ian,
Shouldn't that list start with BE? or 231?

Nope, I can't put any particular powder always at #1. The little run of medium to slow powders I listed is the only group I can put in an order consistently with no shuffling of the order. It's a small segment of the whole burn speed spectrum, but any other spectrum except maybe a narrow band of rifle powders between Varget and H4350 always has more exceptions to the exact order than it does rules.

 

[Rally Hess]

Ian,
I'm thinking about the" what does it do" part of your post. Also what 358156 mentioned about our experiences. I'd be the first to admit having a real love affair with BE, because of it's flexibility at the fast to middle. I'm using it now in most of my pistol from 1.8 to 5.5, and then to Unique. In fact if you put Blue Dot where you have HS6 and Lil Gun where True Blue is , you could cover just about all my handgun and shotgun recipes. I've had real good experiences with Blue Dot in both 1 0z 20 gauge and .44 pistol and rifle. Can't remember the last time I loaded any 2400, but that was most likely in 3" .410.

 

[Ian]

Blue dot doesn't fit in any one place. Put it in a 45 Colt case at 13K psi and it does one thing, put it in a .44 Magnum at 35K psi it does another, compress it behind a heavy slug load in 12-ga and it does yet something different. Put it in a 25K psi .30-'06 load and you might regret it. Use it as a kicker charge under a compressed load of WC860, compared to half a dozen other options, and find it might just do what you want. The other powders are more predictable and in-line with each other in a variety of instances.

Funny you mention BE. There's a reason I wrote that it behaves more like Universal than Unique behaves like Universal, even though Unique and Universal are typically adjacent in the speed charts. BE is easy to ignite like the faster powders (Red Dot, Clays, etc.) but it has a very long burn curve. It develops pressure quickly but that pressure doesn't fall off immediately like many other powders. Unique has the same characteristics of a relatively long push compared to anything in its burn speed class. Universal is easier to light than Unique and more consistent at BE pressures, but has a peakier burn curve, so in a way Universal and BE are quite similar as far as delivering energy to the bullet within a given pressure window.

Take a look at the first post in this thread to get some more insight into "what does it DO?" This is exactly what we're talking about with powder behavior and why it is impossible to rank powders exactly according to burn speed. You can easily see what does what in those examples by observing the burn curves and pressures. https://www.artfulbullet.com/index....-brand-make-really-look-here.1378/#post-26780

 

[Eutectic]

{"Closed Bomb") tests are basically used by powder manufacturers for their own products (maybe competitors). The 'closed bomb' has uniform and repeatable results for the manufacturers use. It allows a particular burn rate area for them in new development and I think is used for lot to lot uniformity as well. Burning rate charts should be looked at only for a general idea.

So many things can influence the exact same load in many different ways. So a 'Loading Manual' is better referred to as a Guide (as some where) The nut at the reloading press and behind the gun needs to learn where the pressures are at. It is a difficult 'art' FAR beyond flat primers and sticky extraction to boot! Add to this that every single gun marches to the beat of it's own drum as to pressure signs and their meanings. A micrometer on the pressure ring of the fired case may be the single most dependable check point. But it's just the 'instrument' usually playing solo. Bottom line...... Listen and watch everything playing in the orchestra!

Pete