[Pulp]

This question was asked over on the Mythbusters Weapons forum. I know some brands of smokeless are temp sensitive, but I had to ashamedly admit that I didn't know about the one true powder. Since my user name over there is Blackpowderpulp (Pulp was already taken) I should know the answers to all the questions, but alas I have failed my alias.:o

[w_houle]

Took some of my BP guns shooting Dec. of last year, the roads were bad so I walked. All three guns were thoroughly cold by the time I had set up and all but one went off without a hitch. One of the caps fell off, so I walked back to the house, put a cap on, walked back to my range and fired that one last shot. It went off just like all the others.

[scrat]

Black powder is not necessarily temperature sensative. HOWEVER it is hygroscopic meaning that it attracks water and soaks it up. Being wet it will not fire. Now as long as you can keep it dry it will withstand cold temperatures. That is the only trick. Now looking at history and all the news. Black powder guns have been found loaded in damp conditions for over 100 years and have igniting not a problem. Same with black powder cannon balls. Now on the opposite side of the spectrum dealing with Heat is different. At a temperature of 300 Degrees black powder can ignite. Now with that if you put a small amount under a magnifying glass under the sun i can guarantee it will ignite. So as far as heat keeping it out of extreme heat is critical. I am sure if mythbusters wants to try it out. on a hot summer day get a junk car and put a small amount on the dashboard and place it under direct sunlight with the windows closed and stand back. So ya

[mykeal]

scrat - just a nit for the newbies: you have a typo - hygroscopic is the word for a material that absorbs water.

Technically black powder is sensitive to temperature: it will ignite if exposed to material at a temperature greater than about 480 degrees F. Below that, however, it's very stable and shows no changes in properties with cold temperatures.

[Old Time Hunter]

BP is not temperature sensitive, but your barrel is. As a safety note, always make sure you reseat the bullet on a loaded gun when going from one environmental condition to another. As the steel cools it contracts and has a tendency to push the projectile towards the muzzle (the powder contracts much less so it does not allow for radial retraction of the bore). So reseat the projectile to maintain consistancy.

[oldpuppymax]

Not temp sensitive in my experience.

[mykeal]

Not temperature sensitive???

Uh, it most certainly is. The Goex MSDS says it's autoignition temperature is approximately 464 deg C (not F as I mistakenly wrote above), or 867 deg F.

I absolutely agree that it does not measurably degrade during or after exposure to low temperatures, but it certainly is temperature sensitive.

[nalioth]

Not temperature sensitive???

Uh, it most certainly is. The Goex MSDS says it's autoignition temperature is approximately 464 deg C (not F as I mistakenly wrote above), or 867 deg F.

I absolutely agree that it does not measurably degrade during or after exposure to low temperatures, but it certainly is temperature sensitive. I think "No, it's not temperature sensitive" is the correct answer to the OP's question in the spirit it was asked. .

At 867° F, we're all temperature sensitive . . .

[BruM]

all chemical reactions are temp sensitive but you must consider absolute temps not the very limited ranges we normally encounter.
Absolute zero is about -459 degrees F so temp effects need to be considered relative to the change in absolute temps. Going from 30 F to 70 degrees looks like a 200+% change to us but on the full temperature scale it is only about a 10% change (40/450). So it is not surprising that bp would not change substantially within such a small percent temperature change.

[Loyalist Dave]

It seems temperature sensitive when firing many volleys with flintlock muskets at a reenactment. As the barrels get hot, the volleys are less ragged, more precise and crisp. I think what happens is the first volley or two the blanks may have absorbed a bit of moisture, but when added to a hot barrel, the heat causes the black powder to dry out to optimum performance, and goes off without delay. So some folks may think that the hot temp effects the powder, but it may simply be drying it out to a uniform degree of moisture, or no moisture at all.

LD

[Bluehawk]

BP does not attract moisture to any meaningful degree...especially when you consider charcoal is insolouble in water. It is it's byproducts after BP has been ignited that are hygroscopic.
I would hardly consider 867 degrees F to be "sensitive"!!!!

[azyogi]

I have ridden to the range on a motorcycle, in august air temp 115F, road temp 140F gun in holster, no idea what the gun temp was no premature discharge, spontainous or otherwise. For most purposes at human tolerable ranges true BP is not temp sensitive. Older pyrodex stored in sealed can in a sealed ammo box likewise shows no measurable degradation, at least as far this desert rat can tell.

[Pulp]

I reckon I should have worded my question a bit more clearly. What I'm referring to is a noticeable drop in performance as temps go below zero, and a noticeable increase in performance as temps go up.

[Bluehawk]

There should not be any noticeable difference in performance of the powder itself...there may be differences in projectile velocity but that would be a factor of cold dry air vs hot humid air such as an aircraft exhibiting better performance in the cool night air vs the hot temps of a summer day! I doubt though you would be able to tell any difference w/o chronographing your gun under both conditions.
Another factor to consider in freezing weather is the lubricants you use to oil up your lockwork...if it's not made for cold weather...is your lock time slowed down because the oil has become sluggish?

[Pulp]

I just got off the phone with Mike Hodgdon of Hodgdon Powders. He said BP is not temp sensitive in the way some smokeless powders are.

[Bluehawk]

Pulp...didn't we tell ya that already?? :banghead:

[GENTLEMAN OF THE CHARCOAL]

Black powder is highly sensitive! Just throw a pound of it in the campfire and wait a bit. You'll notice pretty quickly....(!)

[Pulp]

GOTC, I'm kinda like that myself. Throw me in a campfire and people for miles around are gonna know it.:D

[Bluehawk]

Gentleman said:
"Black powder is highly sensitive! Just throw a pound of it in the campfire and wait a bit. You'll notice pretty quickly....(!)"

There is a village somewhere missing it's idiot !!!! :neener:

[scrat]

Morning GOTC. Youngins everywhere

[GENTLEMAN OF THE CHARCOAL]

Ha ha ha!....