Open Canister Shelf Life of Popular Powders

[Semisane]

I'm looking for some real world experiences/observations here.

I primarily use real black powder which I know from experience does not degrade over time after the canister is opened. GOEX FFFg that was in one of my horns for over two years gave me the same velocity as it did the day I bought it.

But I know little about the open canister life of the various black powder substitutes. I've seen the reports of the pellet forms of Pyrodex and Triple Seven losing power once the package is opened. But what about the loose forms of those two subs once the canister is opened? Do they degrade over time? If so, how long can they be expected to retain their original power. And what about Blackhorn 209? Does it degrade once opened?

 

[sabinajiles]

IME, Pyrodex and Triple 7 powder will retain the same potency for a long time, as long as they tightly sealed. I say this with the caveat that the longest I have kept any before using is about 2 years and when I shot it after that time I did not chronograph the loads to see if there was a difference. BH209 is supposed to tetain potency pretty much indefinitely as long as it is tightly sealed but since I have never kept any for more than 10 months, or so, before using, I can not confirm that.

 

[ronlaughlin]

No help here Van; the reason i purchase powder is to shoot, not shelve.

 

[BuckDoeHunter]

I bought a 5lb jug of BH209 a while back, maybe 4 yrs ago? Of course shortly after that, I started my smokeless muzzleloader projects and didn't shoot much BH209 at all. I still have 1.5 lbs left of that batch. After I got the 5 lb jug, I put the powder into smaller 10oz containers to make it easier for me to handle. Its been stored indoors in a controlled environment ever since. I shot some of that powder last summer and fall, accuracy was the same out of two rifles. I've read that bad smokeless powder can take on a strong acid smell, my older BH209 still smells like a new bottle when opened.

 

[toytruck]

Not sure if this will help, but in my experiences with Pyrodex, Triple 7, and BH209 as long as I use a fresh load from an opened bottle it doesn't seem to make a difference in velocity/accuracy. I don't use pyrodex any longer (too corrosive) but when I did and left a load in an unfired barrel when I did get to shoot it out there was a noticeable difference in power an velocity and of course accuracy.

Triple 7 is the same, but haven't left a load in for several years now as I have shot the gun, Whites .451 or .504. I'm experimenting with BH209 this year as I didn't get a shot in the late ML season so left the load in the Optima to see if there is any change. The range I have to use now doesn't open till May 1st so will try it out hopefully in May. I do have about 10 bottles of triple 7 stored, with absolutely no problems with power, even if it clumps alittle, it goes off an accuracy is still there.

 

[WV Hunter]

I've used Pyrodex RS that was opened, sealed back, stored in a climate controlled place ... and not shot again for about 10yrs. It was as good as a new can when shot side by side. My dad gave the old can to me and I figured I'd try it... shot it all up and even killed some deer with that powder never an issue. That is the only real world experience I have with opened/stored powder more than a year or two old. Within a year or two, I've not ever noticed a difference with any of the powders I've shot.
I got some pellets some time back with a gun I purchased. I don't shoot pellets so I dehydrated them and gave them to my buddy who does. He shot them and said they were fine, fwiw. (I read about dehydrating old pellets online --- no clue if if works, figured it couldn't hurt.)

 

[Confederate rifleman]

Got an at least 10 year old bottle of 3f T7 that's still good as ever. My daughter's Traditions Tracker doesn't have much of an appetite at

 

[dwm]

I vacuum seal my powder when not using it , never had a problem

 

[451whitworth]

Back when I used Pyrodex in the late '80's-mid '90's I had one can of "P" grade go bad after a couple years. I noticed it right away at the shot, it sounded hollow and weak. A shot through the chrony confirmed it as it was 900 fps. It was not stored incorrectly or had the lid left off or loose. It just lost it's potency. A hunting buddy called me a few years ago and was checking his zero on his rifle a month before season. He said his rifle was shooting wild, no grouping. Now this guy doesn't shoot for fun just hunts. I asked him "how old was his Triple 7?" he was using. He didn't know but he had been on the same bottle for years. I told him to go buy a fresh one and try that. Rifle went right back to shooting small groups and still dead on.

 

[Semisane]

That's interesting 451whitworth. The reason I asked the question was because of a similar experience with one of the guys in my hunting club who is a "hunter only" when it comes to muzzleloading. He's shooting a .45 Knight with Triple Seven, using the same powder he bought four or five years ago. When he initially bought the gun I helped him sight it in for a 125 yard zero. It held groups into to a nice two inch cluster at that range.

After that initial sight in the only time he shot the gun was for hunting, and took a deer every year with it during the primitive season.

This year he missed a standing broadside doe at about 100 yards. This guy is a good shot and swore he had a solid double lung hold on the doe when he took the shot. We benched the gun when he returned to camp and it hit nine inches low on the 100 yard target, directly below the aim point. The shot had a hollow sound to me and I told him it sounded like a light load. A second shot put the bullet about an inch away from the first shot, and again had a hollow booming sound to me. Those shots were with powder that had been in plastic speedloaders for the last few years. I didn't think about smelling the powder to see if it had an off smell.

 

[sabinajiles]

Pyrodex and Triple 7 can definitely lose potency if it is exposed to outside air and humidity. If sealed airtight, it will be OK but that can be hard to do after a while of opening and closing the container.