Thread: safe to compress powder during reload?

Originally Posted by Pommy

Please stop.

You have to be aware of the potential for lot to lot variations with every new production run of powder anyway. E.g. I've had some 45-70 gain 150fps with a fresh batch of AR2207.

It really doesn't matter and the data is still fine to follow.

Agree.
As with any manufacturing process there is some variation.
If ADI produced a lot that was out of spec it would be re-worked, if that's possible, or destroyed.

A small amount of lot to lot variation is normal.

Just to add. The explosives industry, including ADI is an incredibly safety conscious and conservative industry. Just a hint of risk and they go into the foetal position.

Originally Posted by blip

I think its to do with the pressure curve. I think I was using 2206 or 2208 in my 303s. The accuracy would have to be pretty bad before you noticed it in an enfield if thats what you shooting. Extra bonus if the pills dont go sideways through the target

Yeah that would make sense.
I have one rifle that has a pretty decent barrel and gets 1 inch groupings at 50M which is supposed to be considered good for an enfield.
I am yet to try boat tails in this yet, but I believe they give the most trouble going sideways in 2 groove barrels or barrels that have plenty of wear.

Originally Posted by Pommy

Please stop.

You have to be aware of the potential for lot to lot variations with every new production run of powder anyway. E.g. I've had some 45-70 gain 150fps with a fresh batch of AR2207.

It really doesn't matter and the data is still fine to follow.

Yeah I see that level of variation just between old bottles for powder and freshly opened. I've got a 4kg of 2209 from 2012 or so with a bit left in it, and it produces 100fps less than fresh 2209. Same with part bottles of old 2208 and 2206H I have from about the same time period

I wouldnt really notice variation as I use old stuff up before opening a new one

Probably pays to store in a dry area and keep well sealed with silica gel inside.

I have been experimenting over winter with dessicant and humidity levels (yeah I know...nerdy aye). I have small Temp/ Hg meters, one is inside my powder storage container with lots of dessicant. And one inside an actual bottle of powder.
After a lot of websearching I believe the range for powder humidity is between 50 and 65% Hg to be optimum for reliable performance. I dont know the outcome yet of all this monitoring, previously I monitored the level of Hg I reloaded at during the session , as powder is hydrostatic it will absorb moisture when exposed to higher levels of humidity than what is present in the storage bottle.
Why am I doing this? well as has been stated previously older powder has a different burn rate than fresh, i believe its due to the long term exposure of higher Hg levels than optimum. Does it matter.... not sure, but I'm trying to find out.
The point I am getting to is in regard to "throwing in some dessicant" this may not be ideal as you dont know the amount of Hg you are removing. You could in theory end up at a level down at 30 or 40% Hg. Dryer powder burns faster and this could be an issue if you are loading up near or over max.

For interest sake the powder storage box i use is IP67 rated the Hg level for the past month has been 42% the powder bottle inside that container is sitting at 52% with a very small dessicant flask in it (from a pill bottle) It has come down from 56% Next time i use that powder i will remove the dessicant and see if the Hg level remains constant or if the bottle (being plastic and therefore semi permable) will continue to loose Hg and end up at the level of the container.
Anybody elses head hurting now? ...wheres my bloody tinfoil hat gone?

Inside a bottle of 2208


interestingly the storage box just went uo 4% or so, its raining but i havent opened the storage box.

I have read of black powder getting wet...then dried out again and being fine to use if slightly faster burning.

Originally Posted by johnd

I have been experimenting over winter with dessicant and humidity levels (yeah I know...nerdy aye). I have small Temp/ Hg meters, one is inside my powder storage container with lots of dessicant. And one inside an actual bottle of powder.
After a lot of websearching I believe the range for powder humidity is between 50 and 65% Hg to be optimum for reliable performance. I dont know the outcome yet of all this monitoring, previously I monitored the level of Hg I reloaded at during the session , as powder is hydrostatic it will absorb moisture when exposed to higher levels of humidity than what is present in the storage bottle.
Why am I doing this? well as has been stated previously older powder has a different burn rate than fresh, i believe its due to the long term exposure of higher Hg levels than optimum. Does it matter.... not sure, but I'm trying to find out.
The point I am getting to is in regard to "throwing in some dessicant" this may not be ideal as you dont know the amount of Hg you are removing. You could in theory end up at a level down at 30 or 40% Hg. Dryer powder burns faster and this could be an issue if you are loading up near or over max.

For interest sake the powder storage box i use is IP67 rated the Hg level for the past month has been 42% the powder bottle inside that container is sitting at 52% with a very small dessicant flask in it (from a pill bottle) It has come down from 56% Next time i use that powder i will remove the dessicant and see if the Hg level remains constant or if the bottle (being plastic and therefore semi permable) will continue to loose Hg and end up at the level of the container.
Anybody elses head hurting now? ...wheres my bloody tinfoil hat gone?

Inside a bottle of 2208
Attachment 280542

interestingly the storage box just went uo 4% or so, its raining but i havent opened the storage box.

Attachment 280543

Thats an interesting read, what shelf life does new powder typically have? I dont see any use by date on mine or anything.
I would imagine that some moisture works its way through the plastic container if its stored in a damp enough place, as you say its somewhat permeable.
I find that silica gel does not absorb that much moisture, but that could be an advantage. Damp rid on the other hand would suck the container dry of any moisture.
What you really need is some way to regulate the humidity so it doesnt drop below your intended level.
What about the shelf life once loaded? humidity could still theoretically make it into the loaded case too, is it just a matter of vacuum sealing and open when ready to use?

@johnd I think you might mean hygroscopic.

Hygroscopicity is a general term used to describe a material's ability to absorb moisture from the environment. There is no standard quantitative definition of hygroscopicity, so generally the qualification of hygroscopic and non-hygroscopic is determined on a case-by-case basis

Hydrostatic pressure, also known as rest fluid pressure, refers to the pressure exerted by a fluid at rest due to the column of that fluid above a specific point in it.

Yeah I have assumed that the slower speeds from "old" powder are in my case humidity related.

So my body is drying out as I age,this why I'm getting slower???? Oh well I shall just have to drink more tea..... Even more wee-wee stops!!!

Originally Posted by Jhon

@johnd I think you might mean hygroscopic.

Hygroscopicity is a general term used to describe a material's ability to absorb moisture from the environment. There is no standard quantitative definition of hygroscopicity, so generally the qualification of hygroscopic and non-hygroscopic is determined on a case-by-case basis

Hydrostatic pressure, also known as rest fluid pressure, refers to the pressure exerted by a fluid at rest due to the column of that fluid above a specific point in it.

Ha yes hyg not hyd, thanks for that. @@Micky Duck you are most likely decicated maybe a higher fluid intake will help.

Man all these "wheelbarrow words" are giving me a headache.... More tea.

Originally Posted by Old_School

Thats an interesting read, what shelf life does new powder typically have? I dont see any use by date on mine or anything.
I would imagine that some moisture works its way through the plastic container if its stored in a damp enough place, as you say its somewhat permeable.
I find that silica gel does not absorb that much moisture, but that could be an advantage. Damp rid on the other hand would suck the container dry of any moisture.
What you really need is some way to regulate the humidity so it doesnt drop below your intended level.
What about the shelf life once loaded? humidity could still theoretically make it into the loaded case too, is it just a matter of vacuum sealing and open when ready to use?

There are dessicant packs used for cigar humidors etc that will maintain your container at a predetermined Hg level. They are pretty spendy. Regarding the shelf life of powder I think the sniff test is still a viable method of seeing
( smelling) if the powder is "off".
If stored well the shelf life seems to be decades at least... even the HPX thats been sold mostly goes bang and its from the 70's and judging from its apearance it was stored in a flooded bunker near the equator

Originally Posted by johnd

There are dessicant packs used for cigar humidors etc that will maintain your container at a predetermined Hg level. They are pretty spendy. Regarding the shelf life of powder I think the sniff test is still a viable method of seeing
( smelling) if the powder is "off".
If stored well the shelf life seems to be decades at least... even the HPX thats been sold mostly goes bang and its from the 70's and judging from its apearance it was stored in a flooded bunker near the equator

Yeah, i think its more the burn rate/ performance that is the critical thing here, i can't expect it to perform the same as fresh stuff, but its still completely usable.
I've pulled apart old CAC ammo thats the best part of 100 years old now with nitro powder inside.
I should try and find some to shoot and see how it performs.