Pyrodex shelf life information

[jtmattison]

Having read on many occasions that Pyrodex has a poor shelf life I contacted Hodgdon on the subject.

Here is their reply:

"Pyrodex is just like black powder in shelf life. It's enemy is
moisture. If it is kept free from moisture by keeping the lid tightly
sealed the shelf life is over 30 years with no measurable change in
performance. This is just like black powder.

We routinely have people send us old cans of Pyrodex from the 70's and
80's. When we test it in the lab, we find it is just like the day it
left the factory."

Hopefully this will clear up any myths, if the claim is true that is.

HD

 

[Runner]

I shoot it up too fast to make that kind of judgement. I bought an old bag with a can of pyrodex in it three years or so ago at the Easter Saturday shoot from a spectator selling out a complete outfit. Another gentleman bought the gun. It was the old lable from way back. It got used with no problems, even tho it was from the 80's at least. Dad is still shooting out of the same can he bought with his first. The Cleanshot, Clearshot, Blackmag type powders have severe storage problems from all reports, but I have never had that problem with Pyrodex myself.

 

[Rebel]

I have had open cans for years that i used up and it worked fine. Don't use it any more since all i have are flinters now.

 

[MikeC]

I was given last year a half full container of pyrodex RS from the mid-80's that worked perfectly. Guy who gave it to me said it was stored on a shelf in his basement.

 

[jtmattison]

The reason I asked this question was because I read something by a muzzleloading "expert", his initials are TB, and he said Pyrodex had a poor shelf life.
I use real BP, Goex. Maybe if I ever get into a pinch I'll try Pyrodex.
It's good to know it won't poop out after sitting on the shelf for a while like TB said.

HD

 

[Rebel]

Ahhh come on, how ya gonna believe anything from someone with the initials T.B.?

 

[Bearbait2]

Deleted

 

[Slamfire]

My son left a can here that must have gotten some moisture in it, as the powder was all clumped up. I shredded it by hand, and it seemed to shoot as good as it did when new. :winking:

 

[armymedic.2]

i have had some cans that stuck around for 5-6 years. never had any problems at all with them. stored in safe

 

[Blizzard of '93]

Yeah I've had some Pyro for 5-6 years (bought a half-case) no problem. should be kept out of sunlight and dry place.

 

[Mad Monk]

And the funny part about this is that until recently if asked the same question Hodgdon would reply that once the seal was broken on the container the suggested shelf-life was one year.

Trouble is that they change stories depending on who they are dealing with.

 

[jtmattison]

And the funny part about this is that until recently if asked the same question Hodgdon would reply that once the seal was broken on the container the suggested shelf-life was one year.

Trouble is that they change stories depending on who they are dealing with.

Very interesting :hmm:

I guess the only way to know is to conduct some tests.

O.K. who has a chronograph, some Pyrodex, a year to wait for the powder to age after being opened, and the ambition to take on the project?

I'll stick with Goex.

HD

 

[Mad Monk]

HD,

Going back to the mid-1980's.

Lyman had a young guy working as their East Coast rep for the ml gun line. I would see him once or twice a year when he would show up at Dixons. He and I talked a number of times. I would look at bulged or burst barrels for Dixon and then I would have to copy the reports to the Lyman rep.
One day I got a letter from him. Asking about the chemistry of Pyrodex and what he had experienced. He was shooting a Lyman sidelock percussion rifle in the deer season up there. He sighted the rifle in a few weeks before their deer season.
Loaded the gun when he got out of the car the day of the hunt. Went to his stand and waited. Next thing a big buck comes within range. So he lines up on it and fires.
He said the shot sounded kinda week and he could see the ball going towards the deer in an arc. The ball hit the deer and simply bounced off its side.
So as soon as he goes back to work he takes the rifle and the powder in and fired a number of shots over the chronograph. Real wide spread in velocities with 5 shots fired. A low around 800 fps mv and a high of 1400 fps mv. No decent accuracy.


A few years back I had a bp cartridge shooter contact me. I had dealt with him when he had been shooting ml rifles.
He had loaded a bunch of .45-70 rounds with Pyrodex RS. He was out shooting at the range one day. He fired a round and it sounded kinda dull. When he dropped the breech on the Sharps rifle the spent case came flying out. Hit the breech block and went flying off to his side into the woods trailing smoke.

Facts of life here.
Pyrodex will store for long periods of time but it is more critical of any moisture picked up during storage. Black powder is more forgiving in this. When they make Pyrodex they pack it at around 1% moisture content. The patent on Pyrodex describes this. That if they were to dry it completely it would not work as well. They did not know why this 1% moisture content was critical to the performance of the powder only that it played some part.

Now Pyrodex uses elemental sulfur in with potassium perchlorate. About 8 parts of elemental sulfur and around 17 parts of potassium perchlorate.

In Tenny L. Davis's book titled: Chemistry Of Powder & Explosives there is a section covering the old corrosive chlorate and perchlorate primers used in metallic cartridges. The author cautions against the use of elemental sulfur with a chlorate or perchlorate because in the presence of small amounts of moisture you may see a "self-souring" reaction. A chemical reaction between the sulfur and the chlorate or perchlorate. At first the primers become a bit erratic in their behavior in igniting the smokeless charge in the cartridge. Eventually the primers simply go dead.

So if Pyrodex, during storage, is allowed to pick up moisture this will happen to it.

Given the same relative humidity, Pyrodex will pick up about twice as much moisture (by weight) compared to a well made black powder.


After the founder of Hodgdon retired things sort of changed with them. The founder was straight up and blunt. He would tell you flat out that yes Pyrodex was corrosive and then tell you to clean the gun as you ought to do in any case. Once he was gone they tried to claim it was not corrosive.

At different times Hodgdon has had one of their staff on various message boards. Waving the flag and trying to make jerks out of anyone who did not sing the praises of their products. I ran into him at first on the old BP list out of cinnamon dot com a little more than 10 years ago and a few years ago on the SASS board. He rather slowly learned not to argue powder chemistry with me.

 

[paulvallandigham]

Attaboy, Mad Monk. Don't let those weasels get the best of you when you know you are right! :thumbsup: :hatsoff:

 

[Mad Monk]

Paul,

The point is that there is no such thing as a perfect powder. Least of all any of the subs. There are pros and cons in working with all of these powders. So you educate the shooters on how to deal with certain aspects of their use.

An educated shooter is a safe shooter.

 

[Dave Rosenthal]

:applause: :applause: Mad Monk you're the greatest. This explains what happened to a friend of mine when the ball barely left the barrel one day :shake: . He was using the fake stuff in the summer in Jersey with a very high humidity. We heard a soft pop and the ball didn't hit the target...we yanked his crank and told him to try reloading the same ball, but use real Black instead :redface: .

He borrowed powder for the rest of the day and placed in the top third of his division. :winking:

Keep-up your good works, Dave

 

[Mad Monk]

I only scratched the surface on some of the nonsense in the powder business. When one of them wings a Cheap Shot at me I go off on a CorpoSwine Jihad.

 

[Runner]

Mad Monk, I love your posts. You understand these things very well, and I don't. I have a powder horn hanging with RS in it that is over a year old, and we keep the windows open most of the time. I have been doing that for about 30years now with Pyrodex in it. Still my first made in India cheap horn. I have never hit that particular problem with it. Not saying that you are wrong, because I don't think you are. Just a real world report on what it does here.

 

[paulvallandigham]

Runner : If the powder horn is full, and you have not pulled the plug on the horn in years, there is no way for moisture to get into the horn, and spoil the powder. The problem comes from exposing the powder to moisture. The more air in the horn, the more likely it will take and hold moisture, from the humidity in the air, when you pul the horn's plug, or stopper. If the horn is full, there can't be much air in there, and that means less moisture will enter the horn if the stopper is pulled.

I have rarely heard complaints about Pyrodex, as to deterioration. I have heard lots of complaints about the more recently manufactured subs, which all seem to be based on ascorbic acid compounds. Ascorbic acid readily combines with water and changes its rate of oxidation. I see shooters all the time leaving their powder cans open in the trunks of their cars, and, occasionally, on the loading bench at the club, if a range officer is not paying attention and jumping for such an unsafe practice. An hour or so on a hot humid day with the lid off is probably all that is needed to spoil some of the new subs. When you ask guys why they left the cap off the can, they will usually say, " I forgot !" In actuality if you question them, they did not know how important it is to keep the cans closed to moisture, and have not (yet) experienced weakened powder.

 

[Mad Monk]

Runner,

I had looked at how well a powder horn protects BP against moisture. Filled my hunting horn and hung it in the basement. Heated in the winter but no dehumidifier in the summer. Hung it in the rear of the basement where the walls and floor sometimes get wet in late summer with 100% R.H. readings.

With the horn full I saw no increase in moisture in the powder in the horn. Every few weeks I would pull 100 grains from the horn and check moisture content.
The horn had a tapered wooden spout peg. The top had beeswax as a form of a seal around the butt plug.

The horn will still "breathe" with daily changes in atmospheric pressure. But given a full horn with little air space you simply don't get enough air moving in and out of the horn to give a good amount of moisture to get to the powder.