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Powder Burn Rate Chart

Posted: 24 Feb 2018 07:55
by Macd
For years I have used the Hodgdon or ADI burn rate charts to help inform my forays into hand loading where published information is scant. Yesterday I came across another chart which is much more complete and has powders from many other manufacturers. I will repeat, for the newcomers to the hand loading game, the caution that simple direct comparisons between powders even with the same burn rates is not possible. The information must be used with other data from trusted sources. Reference to hand loading tools such as Quickload are recommended to also assist in making decisions on powder appropriateness and charge amounts. QL is not a loading manual and to treat its output as infallible is to court nasty surprises when the trigger is pulled. Okay here is the link to the chart. It is a pdf so can be saved on your local device.

http://www.t2ammo.com/data/_uploaded/fi ... 0Chart.pdf

Re: Powder Burn Rate Chart

Posted: 24 Feb 2018 08:48
by farmerjim
Thanks much.
This is better than the other 2 charts that I have.

Re: Powder Burn Rate Chart

Posted: 25 Feb 2018 00:57
by cj8281
A couple of things I found kind of strange on it, they list promo and red dot as two different burn speeds yet promo is just a denser version of red dot, they are the same speed. Also hp-38 and 231, they show them as different speeds but they are the same powder, just different packaging.

Re: Powder Burn Rate Chart

Posted: 25 Feb 2018 14:32
by Macd
cj8281 wrote:A couple of things I found kind of strange on it, they list promo and red dot as two different burn speeds yet promo is just a denser version of red dot, they are the same speed. Also hp-38 and 231, they show them as different speeds but they are the same powder, just different packaging.
I can't really answer why. They caution:

"WARNING!
Listed burn rates are approximate. Numerous variables preclude the possibility of exact burn rate comparisons.
Exercise proper handloading techniques and safety precautions at all times when handloading ammunition"

ADI shows the powders as equivalent if within 5%. Hodgdon shows Alliant Red Dot and Promo as one step different as they do HP38 and W231 but their chart shows no duplicate placement so ??? The chart in the Lee 2nd edition shows hp38 and W231 at identical rates. Alliant in their latest reloading guide indicates Promo is slower than Red Dot by one step, whatever that means. I wonder if lot to lot variation might even reverse their relative positions. Sometimes I wonder how much is science and how much is marketing. Just another reason to start low and work up for every new component including powder lot.

Re: Powder Burn Rate Chart

Posted: 25 Feb 2018 18:00
by cj8281
Where would I find this guide by Alliant? I was just on their website and saw that they list them as the same.
http://www.alliantpowder.com/products/powder/promo.aspx

Re: Powder Burn Rate Chart

Posted: 26 Feb 2018 01:17
by Macd
cj8281 wrote:Where would I find this guide by Alliant? I was just on their website and saw that they list them as the same.
http://www.alliantpowder.com/products/powder/promo.aspx
Page 11
http://alliantpowder.com/resources/cata ... atalog.pdf

Re: Powder Burn Rate Chart

Posted: 26 Feb 2018 06:53
by Ranch Dog
I appreciate the chart Macd; it is the best layout I've seen. I think most of us understand the complexities and hazards of using a burn chart like this to relate a load of one powder to another; it's a bad practice. The best point I can make is the relationship of IMR Trail Boss and Hodgdon's International. I know of very few guys in the US that have used the latter, but a lot of new reloaders are coming on board because of Trail Boss. Talk about a powder that is easy and safe to load! You don't even need a scale or a scoop to measure it.

During the OHB years of reign, with powders tough to find, I ordered a 4 lb jug of Clays and was sent International in error. Some of that is on Hodgdon as Clay's is labeled "International Clays" or at least was. When I contacted the supplier concerning the error, they stated, "keep it, we cannot give it away!", but sent me the Clays.

International is the most volatile powder I've shot. It makes the performance of Lil'Gun appear like a roll of paper caps for a toy pistol. Miss this by a tenth of a grain and you can send the barrel and what surrounds it in several different directions. After working with the pressure trace equipment, not a lot bothers me because I see how safe the components we are provided with along with the data to use them are. We are very lucky these days. International scares the CHIT out of me.

I was able to find and use AP-50N data, but there is no crossover as might be suggested. I was told by our brothers in Australia that is was same but damaged a pistol. Hodgdon had a cow when I talked to them. I see a lot of powder called the same, but unless you find both powder manufacturers claim it the same, I would not consider the internet claims valid.

As far as my International goes, the only application I have found for it is with my raccoon killing 25 Auto. I use 1.1-grains of it. 1.2-grains will blow it up.

So back to the chart and the relationship of powders. There sits International one step off Trail Boss. International is a heck of a lot easier for someone to come by that Trail Boss. I'm only saying to be very careful in how you use a powder list; there is no pressure generating comparisons made between powders on the list, only how fast they burn against one another other. The rate of the burn does not relate to pressures generated.

Re: Powder Burn Rate Chart

Posted: 26 Feb 2018 11:08
by Macd
Well said RD. :t

I shared the chart as it is the most inclusive one I have ever found. I always include cautions when I post even though I know most of the regulars here have more knowledge and experience than me. Like it or not many people use these forums to help them learn how to hand load. We all know how many times we have read "It is close to XYZ in the burn rate chart." The new loader reads that and checks a chart and the statement is true. We know it doesn't mean the powder is a safe substitute but the new loader may not realize this. While things are better now, go back a few years and we were all scrambling to find substitutes for loads when our regular powder wasn't available. Imagine how the frustrated the new entrant to the game felt. The plethora of new powders or least names is a challenge. Another problem is that charts change over time but "Google" doesn't know this and will happily show you a chart that is no longer current. Human error is also a factor and we all agree even published data should be checked against at least two credible references. Of course this also has some issues as referenced data may be developed differently by the originator. Finally if you don't have a chronograph and know how to use it then you are handicapping your ability to create safe loads. Guessing the speed of a bullet is like guessing the speed of a vehicle. It ain't going to hold up in court.

We know hand loading is not a hobby for the casual observer or the easily distracted mind. Unless someone is willing to spend time researching, verifying, checking and rechecking information then working up from minimums in published loads is highly recommended. So far, "Touch Wood" my biggest error was in mixing up OAL for two rifles of the same calibre. (Chronograph told me something wasn't right.) Doesn't make me "Cocky" though. I still apply the "Thin ice" approach. Move slowly, check continuously and back away at the slightest sign of danger.

Re: Powder Burn Rate Chart

Posted: 27 Feb 2018 15:15
by Ohio3Wheels
Macd wrote:<snip>
We know hand loading is not a hobby for the casual observer or the easily distracted mind. Unless someone is willing to spend time researching, verifying, checking and rechecking information then working up from minimums in published loads is highly recommended. So far, "Touch Wood" my biggest error was in mixing up OAL for two rifles of the same calibre. (Chronograph told me something wasn't right.) Doesn't make me "Cocky" though. I still apply the "Thin ice" approach. Move slowly, check continuously and back away at the slightest sign of danger.
Good policy it will go a long way toward keeping your body parts where they belong and you gun parts the same.

Make smoke,