Impact sensitivity of BP


PDA






Pulp
May 18, 2008, 01:46 PM
There is a common myth going around that BP is very impact sensitive. I've been unable to find an MSDS on BP that would confirm or deny the myth. I did find one site that said only, "BP is not particularly impact sensitive".

This question comes from a topic on the Mythbusters weapons forum where John Wayne blows up a keg of BP in the movie "Sons of Katie Elder".

I personally don't believe a .38-40 would have the energy to accomplish this, however I also realize that John Wayne was shooting the rifle. If JW told it to blow up, it's gonna blow up.;)

Anyway, do any of y'all know of any links to actual numbers?

If you enjoyed reading about "Impact sensitivity of BP" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
rcmodel
May 18, 2008, 02:36 PM
I have personally shot dynamite sticks with a 30-06 and failed to do anything more then scatter pieces of them around my dads pasture.

Black powder in a drum?
Perhaps if the bullet created friction or a spark from a metal drum to cause enough heat.
Maybe.

You can pound grains of black powder with a hammer on an anvil, and it won't pop.

But there are several references in Hatcher's Notebook about powder explosions caused by bullet impact.
But this was smokeless rifle & pistol powder stored in 150 pound containers.

In one instance, a huge flashfire killed a well known hand-loader & experimenter of the time named J. Bushnell Smith.
He accidentally (ND) fired a 30-06 into 5 150 pound drums of rifle powder stored in a room next to his gunshop.

The resulting flash fire cooked him in his tracks.

rcmodel

scrat
May 18, 2008, 02:53 PM
impact sensitivity i doubt it especially when i load. As im always making sure my bullets are packed hard and tight. on my revolvers it usually as hard as i can pull the handle down to pack the ball tight against the powder

Redd Flynt
May 18, 2008, 03:03 PM
It may be possible to get an impact detonation but not very probable. All explosives are subjected to various testing to determine the specific qualities of each compound or mixture. The impact test is one of those used. Another is the rifle bullet test conducted with a standard military .30 cal ball round. BP does not ignite under either standard test.

Consider that BP was used as the bursting charge in most artillery projectiles to the end of the 19th century. It had to endure the acceleration and heat of being fired and then the almost instant deceleration of impact.

Very unlikely that most of us ever subject BP to the extremes cited. BP is literally "Bullet Proof", a claim not shared by very many explosives. When DuPont discontinued the manufacture of dynamite in 1972 and introduced Tovex, one of the big advertising gimicks was that Tovex was Bullet Proof. This was a claim many of us in the industry had to test for ourselves.

A rapid introduction of heat is about the only thing that will ignite BP. The insensitivity to ignition coupled with a shelf life that has yet to be determined will ensure its longevity.

Redd

Rachen
May 18, 2008, 05:43 PM
Actually, I thought about this question many times before. One day, just to test it out, I placed BP between two plastic picnic plates, glued the whole thing together, and used them for targets.

Range: 15-20 yards.
Gun: Pietta 1858 NMA
Load: 30 grains H777. 190 grain Buffalo bullet.

I hit all targets all right, but the best I could do too, was just scatter some BP all over the ground.

Now if it's FLASH powder or TANNERITE, I guess it's going to be Fourth Of July.

I have personally shot dynamite sticks with a 30-06 and failed to do anything more then scatter pieces of them around my dads pasture.

I am surprised that the dynamite didn't go off when hit with .30-06 rounds, even from a long distance, these rounds pack much kinetic energy, and dynamite is meant to be impact sensitive, that is why they were designed to go off with specialized blasting caps, right? Or am I missing something here?

jimrbto
May 18, 2008, 09:11 PM
I think that the only reason the dynamite did not explode was that that dynamite was not nitroglycerin based. Nitro based explosives are extremely shock sensitive and just will not take a gunshot without detonating. I was involved in the investigation with a similar incident in Oregon, stick of dynamite, fence post, and I believe a .22 rifle. BOOM! The local sheriff wanted to determine exactly what happened as the gent. was not conscious.
Jim

Harve Curry
May 19, 2008, 10:14 AM
I saw the aftermath of a inline muzzleloader that had been mistakenly loaded with three 50gr pellets Pyrodex and sabot bullet, then again with the same load. The efforts to remove the stuck charges the barrel and breech plug was removed and the first 3 Pyrodex pellets were removed. But the charges between the two sabot bullets wouldn't budge. The rifle was fouled. A steel rod and hammer was used while the muzzle rested on the hammer's boot. Several whacks and it detonated the charge causing one bullet to go through the boot/foot and the other came backwards out the breech pushing hammer and rod along with it. That bullet entered across the hammer's eye and lodged behind the skull above the eye lid.
Whatever the stuff is to help ignite Pyrodex pellets on the end is probably what ignited.

arcticap
May 19, 2008, 03:07 PM
There was a post on the MLF about a discharge while either pulling a ball or ramming one (I do think it was being pulled though). The way it was described was that if there's grains of black powder on the wall of the bore along with lubricant, that it may be possible that during ramming or pulling a ball, the combination of friction/pressure/heat causes the lubricant to reach it's flashpoint which in turn can ignite the black powder charge and cause a discharge.
I'm not certain if a lube can be volatile enough under certain situations to be ignited or not, but even air gun manufacturers recommend using only certain non-volatile lubricants to prevent dieseling. Maybe this scenario could be caused by trapped vapors/vaporization under certain conditions?
If a fire can be started simply by rubbing sticks together, then I believe that anything is possible within the confined area of a gun bore.

Anyway, "volatile" is defined as:

Chemistry - Evaporating readily at normal temperatures and pressures.
That can be readily vaporized.

I wouldn't sweat over it too much guys, just try to keep body parts away from being in front of the muzzle whenever any powder is in the barrel. :)

Ifishsum
May 19, 2008, 03:42 PM
A steel rod and hammer was used

There's a reason that rods meant for BP are brass or wood/fiberglass with brass ends. No sparky.

The black stuff on the end of Pyrodex pellets is real black powder - much easier to ignite than the Pyrodex itself.

theotherwaldo
May 20, 2008, 07:02 PM
I think of all of the black-powder guns that were designed to use stacked, sequentially-fired loads...

DuncanSA
May 21, 2008, 12:27 PM
When I was young and stupid (I'm older now), we used to have lots of fun shooting at dynamite sticks wedged into crevices in trees. Depending on the amount of dynamite used, some most impressive explosions ensued! Working for a prospecting company we had lots of free dynamite, and boredom in the african bush sometimes led to passtimes that would be frowned upon in civilized places.

I have never tried hitting or shooting into quantities of black powder, but I have the deepest respect for the stuff and think it would be a very bad idea.

Jim K
May 21, 2008, 02:10 PM
Hi, Jrimrbto,

What dynamite is not nitro based? There are some explosives that are not impact sensitive, but dynamite is not one of them.

Black and smokeless powder are not impact sensitive, but a blow can strike a spark. In the Smith case Hatcher reports, the powder was only inches from the gun muzzle and it is likely that the muzzle flash or burning powder from the gun set off the powder, not the impact.

Hatcher's point was that under some circumstances, smokeless powder can be explosive and not just burn rapidly.

Jim

Cosmoline
May 21, 2008, 02:18 PM
As I understand it, you cannot set off black powder by simply pushing hard with your ram rod or even hammering it, absent some spark or other ignition source. But I have also heard that this is untrue, and you have to be careful about not setting your loads too tight.

PTK
May 21, 2008, 02:18 PM
In my experience, nitroglycerin based explosives (Dynamite, for example) are not all that impact sensitive unless they've "sweated" out some of the NG onto the wrapper. That was the entire point of making them - that they were much harder to set off and thus safer.

OFT
May 21, 2008, 03:17 PM
I have set off a pound of GOEX FFg with a shot from a 30/06 but I imagine that a spark from the slug hitting the can was the cause. Made a fine smoke cloud.:evil:

arcticap
May 21, 2008, 03:41 PM
Handle with care. Avoid impact, friction, heat, sparks and open flame.
http://www.goexpowder.com/handling.html

In many places, there's a lot of tiny iron particles contained in surface dirt. Extremely small bits of iron can become wind-borne as dust, and it can even become aerosolized and spread around the globe that way.

(Don't read this! :D )http://www.cru.uea.ac.uk/~e118/publications/ironreviewpapersubmitted.pdf

This makes me wonder about whether errant iron particles could be present on the surface of lead conicals or even deposited inside of a gun barrel where friction can cause it to become a "1 chance in a trillion" spark?
Just because folks aren't aware that it could be present doesn't mean that it can't be there. So it follows that the stronger that the BP is impacted, then the greater the likelihood that friction could create an ignition spark of some sort. After all, the gun barrel is steel and could even be the source of a microscopic steel particle.
If there wasn't any BP ignition threat resulting from simple yet strong impact with BP upon loading, then why are there so many warnings about avoiding impact with it?
Is it an unnecessary warning that the sky is falling, or is there really a rational basis for it?
It seems simple enough, impact promotes friction, and the stonger the impact the more the friction.
A warning is a warning, and Goex does deliver this warning.
For some folks, the lower ignition temperature of BP might be a good enough reason to only use BP substitutes and not real BP.
BP does theoretically seem to present more of a potential hazard, doesn't it?

mykeal
May 21, 2008, 08:44 PM
f there wasn't any BP ignition threat resulting from simple yet strong impact with BP upon loading, then why are there so many warnings about avoiding impact with it?

Because the US government, in it's official EPA description of black powder, erroneously says that it's impact sensitive, and the manufacturer's/distributors know that the government's declaration, even if totally and completely in error, is sufficient to create the basis for successful litigation. You see, the EPA does not have to prove they're right; they only have to make the declaration and a plaintiff's lawyer can use that declaration as fact. The manufacturers/distributors have no choice but to continue to perpetuate the falsehood.

GRB
May 21, 2008, 09:11 PM
As per Encyclopedia Britanica at: http://www.britannica.com/EBchecked/topic/198577/explosive/82365/Ignition-of-black-powder:

Black powder is relatively insensitive to shock and friction and must be ignited by flame or heat.

I would imagine that the source for that quote is fairly reliable as they actually sell their encyclopedia as opposed to something like Wikipedia.

All the best,
Glenn B

jimrbto
May 21, 2008, 11:50 PM
Jim
Non-nitro based dynamite has been manufactured in at least three forms, all are based on ammonium nitrate. Two of these were jelled, one was cap sensitive and the other was not and required a booster to make it detonate. These were formulated, I believe, to avoid royalty payments.
Further, there is no way in hell I want to be anywhere near a stick of nitro based dynamite being shot at; whether it was sweating or not! ! You have no idea just what has gone on inside that stick, when you can see it on the outside guess what may be inside.?!?
Jim

Quoheleth
May 22, 2008, 12:11 AM
Because the US government, in it's official EPA description of black powder, erroneously says that it's impact sensitive, and the manufacturer's/distributors know that the government's declaration, even if totally and completely in error, is sufficient to create the basis for successful litigation. You see, the EPA does not have to prove they're right; they only have to make the declaration and a plaintiff's lawyer can use that declaration as fact. The manufacturers/distributors have no choice but to continue to perpetuate the falsehood.

Actually, I saw this on CSI Miami on Monday night. Caleigh was in the lab when a a loaded cartridge fell off the table, struck the floor at an approximate 40 degree angle on it's base - the primer not touching the floor or another object - and the round discharged, setting off a chain of events that resulted in a lab fire. It was discovered that the round was loaded with BP and - as everyone knows - BP is terribly unstable, especially when it is old Russian ammo.

This from the Gospel according to St. Bruckheimer. You know it's true when a TV CSI says it's so. :banghead:

Q

If you enjoyed reading about "Impact sensitivity of BP" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!