Do NOT use Black Powder in a Lee Pro Auto-Disk Powder Measure

[junkman_01]

That may be what it says, but TRY it! It won't go off.

 

[[email protected]]

All I can say is go set you up a can of Black Powder at 25 yds, and shoot it.
Use something modern like a 30-06. You will have all the "Impact" you would
want, and it won't go off.

 

[junkman_01]

I know Phil. Old wives tales die hard. Even the government perpetuates them.

 

[arcticap]

Impact sensitivity is based on scientific testing

There appears to a difference in the impact sensitivity of various black powders depending on whether the striking surfaces are extremely polished or not.
It appears to be mandatory that impact sensitivity testing equipment surfaces are to be highly polished.
Therefore the analogy of striking black powder in the driveway with a hammer is not the same as scientifically testing for the impact sensitivity of black powder with the proper equipment.
Please read the entire Shooting Accident!! thread below to understand the possibility of how under certain conditions, some black powder can become more impact sensitive, particularly when a black powder and some of the granules have become partially degraded.

Shooting accident!!

http://americanlongrifles.org/forum/index.php?action=printpage;topic=2793.0

...The most logical explaination is that when the top charge was rammed down onto the other charges there was an impact shock ignition of the powder comprising the second charge in the bore.

Normally black powder is said to be only moderately sensitive to impact shock ignition that is based on a standardized laboratory test. This test is a fairly common one in the chemical industry used to quantify the impact shock ignition sensitivity to a variety of chemicals.

The standard test uses a holder with a 1/4" hole machined in it. A 1/4" diameter plunger goes into this hole. These two items have highly polished surfaces. The critical surfaces are the portion of the plunger that rests on the sample being tested and the bottom of the hole in the holder where the sample being tested rests. Any surface imperfections may act to give false readings. This would be readings at impact energy levels below those with highly polished surfaces.
This sample holder is affixed to a large heavy base to prevent rebounding that would cause multiple impacts with one "hammer" drop.
There are a pair of rails that extend vertically above the specimen holder. A 2 Kg weight rides on these guides. The guides are calibrated for height. When you run this test you have a specified weight of sample in the holder with the plunger resting on the sample. You raise the "hammer" to a specific height and release it. It free falls and strikes the plunger. If there are no ignitions in ten drops you move to a greater height and do 10 more drops. You note the greatest height at which 10 drops give no ignition and continue increasing the height until you have 10 ignitions for 10 drops. This data then goes onto a graph. Most of the time the data forms an "S" curve on the graph.

But the whole test is based on the fact that you have the plunger and the base with a specified amount of surface area that is highly polished.
In this test you have the kinetic energy of the falling weight (hammer) being converted to heat energy where the grains of powder would be in contact with the face of the plunger and the bottom of the hole. Any surface irregularities would concentrate the force in very small areas which would greatly increase the amount of heat generated on the contact points.

There have been several deaths and serious injuries with smokeless cartridge rifles where loaded cartridges were stuck in the chamber. The shooter would take a rod and run it down the bore until it touched the bullet. Then take a mallet and hit the rod to drive the cartridge out of the chamber. The fatal accidents involved full cases of powder where the base of the bullet rested directly onto the grains of smokeless powder. One or two blows was all it took to light the charge in the cartridge from heat generated where a few powder grains were in contact with the base of the bullet.

In the case of a round ball in the bore with heavy blows on a ramrod you have a very small area where this kinetic energy is being converted to heat. If the powder was old and the grains crumbling it would be easier to ignite in this manner compared to a good hard-grain powder.

In the fall hammer test the saving grace with black powder is that the blow from the falling "hammer" ususally crushes the grains which adsorbs, or dampens, the blow. If you were to rapidly drop the hammer several times you could easily get ignition of the powder since each blow would add a bit more heat to the powder in contact with the face of the plunger.

This is one explosive test that gives data not totally applicable to field use. It is used to compare various explosive compositions. The data obtained is at best relative and certainly far from absolute.


E. Ogre

 

[junkman_01]

I read the article you supplied and I come away with this....

"Any surface irregularities would concentrate the force in very small areas which would greatly increase the amount of heat generated on the contact points."

So my hammer and concrete test would be MORE conducive to getting ignition, which it did not! I don't need no stinkin' laboratory to show that BP is very hard to ignite by impact or pressure. Thank you for proving my point.

 

[arcticap]

Mad Monk is a recognized black powder manufacturing expert and author. His statement clearly mentions the likely possibility of "impact shock ignition" with regard to the accident discussed in the thread.
He's also familiar with impact sensitivity testing equipment and he explained the potential increased impact sensitivity of degraded black powder.
His opinion is based on scientific knowledge and facts. Not all black powder is the same under all circumstances and there are differences that can be distinguished. So while one form of black powder is not very impact sensitive in one instance, another black powder can be in another instance.
Thus the driveway experiment may not correlate to what can possibly happen inside of a powder measure with a different powder at a different time.

...The most logical explaination is that when the top charge was rammed down onto the other charges there was an impact shock ignition of the powder comprising the second charge in the bore.

Normally black powder is said to be only moderately sensitive to impact shock ignition that is based on a standardized laboratory test. This test is a fairly common one in the chemical industry used to quantify the impact shock ignition sensitivity to a variety of chemicals.

 

[junkman_01]

The 'Mad Monk' also said....
"This is one explosive test that gives data not totally applicable to field use. It is used to compare various explosive compositions. The data obtained is at best relative and certainly far from absolute."

My simple field test came up with a different result. BP is hard to ignite unless you supply sufficient HEAT.

Now it's your turn to refute MY findings.

 

[Jaymo]

So, I need to put a few grains on my anvil and hit it with my 3 pound hammer.
Sounds like a good experiment to me.

Speaking of fouling, I shot my AK pistol and new .45 pistol with Tula ammo today.
Nasty stuff. Neither gun liked it too much.
It was dirtier than BP.