Method of mesuring black powder burning speed

[jimjones]

Is there a good method of mesuring black powder burning speed?

 

I did my first batch of blackpowder and wanted to know if it is fast or not.

[SharkWhisperer]

Is there a better way of spelling "mesuring" ?

 

Is Jim Jones really your given name or a twisted moniker? Folks, google "Guyana Jim Jones".

 

So...how fast was it? How did you arrive at this speed judgement? For what purpose are you making BP?

 

Tell us a little about yourself and your ambitions...

Edited February 5, 2020 by SharkWhisperer

[NeighborJ]

Baseball testing is the standard method. 3" mortar, baseball and a stopwatch.

[jimjones]

in this link they use two methods http://www.wichitabuggywhip.com/fireworks/charcoal_tests.html

 

the simplest method is to burn a powder trail spread on a V-shaped iron and measure the time it takes to burn trough 2.5 feet of it.

 

I did a similar test using a powder made with briquette charcoal and granulated with 50% isopropil alcohol without dextrin. The burning speed was about 13cm/s or 0.43feet/second, pretty slow compared to the ones in the link above.

I know briquette is not recommended, I will try again with another charcoal.

[NeighborJ]

That method of testing is subject to a huge margin of error. A spark can easily leapfrog 2.5 feet igniting the entire length almost instantly.

The baseball tests or "shuttle" testing is a much more accurate method and tests the powders ability to do the work that maters. This is "the" method used at PGI.

There are powder testing guns with a spring loaded spoon and a slide to accurately measure how far the spoon was pushed. These are rare to find and aren't available to everyone so the shuttle cock method is still the choice for those curious about comparing powder speed.

[Carbon796]

A spolette can also be used to gage BP quality.

[DrJones]

Thanks for the clues on rating BP burn rate and effectiveness. Has anyone used a smaller mortar lift test, perhaps with a golf ball instead of a baseball? Thanks in advance.

[chuckufarley]

Thanks for the clues on rating BP burn rate and effectiveness. Has anyone used a smaller mortar lift test, perhaps with a golf ball instead of a baseball? Thanks in advance.

That should work fine. It might not compare to people testing with a baseball, but it will allow you to measure the difference between your own batches of bp, to see what changes have what effect.

[Mumbles]

There are golfball mortars and people who play "pyro golf" as a method to test their powder. I believe there's an article in one of the Best of AFN anthologies. There are a few caveats:

 

1. Typically a finer grain powder than might normally be used for lifting shells is required.

2. You'd probably be best off having some commercial 4FA or 2Fg or something as a standard or calibration.

3. Being smaller diameter, the amount of BP you use tends to matter a little more. Too low of an amount probably wont give the most accurate impression.

 

They recently did a pyro golf test session at my regional club. They used a poorly measured 2g of alleged 2FA powder, but the grain size was not really enforced. They mentioned that they'd probably use 4g next time. To give some relative values, commercial Wano clocked in a 2 sec flight time, and commercial Wano Scheuzten powder clocked in at 3.5 seconds. Goex "lift" powder from Bear River clocked in at 1.75 sec. Homemade powders varied between 2 sec (tree of heaven) and 4.5 sec (narrow leaf cottonwood) with a couple in the middle that didn't specify charcoal variety, just who made it.