Does Powder Get Stale Out of the Can?

L

lwestatbus

New member
I use a Lyman Brass-Smith powder measure and a Lyman Brass-Smith powder trickler. Before a session I load both of these with propellant.

I have been in the habit of pouring powder back in the plastic jar after each session unless I know I am going to come back for more the very next day. I live in Florida where summers are humid, though all of my equipment and supplies are in an air conditioned condo.

I am wondering if my powder will deteriorate if I leave it in these dispensers for a week or maybe even a little more. The powder measure has a pretty tight fitting cap and an old Hogdon's jar cap fits pretty closely to the top of the trickler.

Also, since I am on the topic, does anyone have a tip for speeding up the process of 'charging' the powder trickler?

Thanks.
 
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Smokeless gun powder can only gain or lose a tiny percentage of weight due to moisture. Just weight some charges to verify the desired weight is thrown before beginning to reload. As long as the temperature doesn't dip below freezing, your powder will be fine for many years.
 
Depends on the material of the measure.
I leave my Dillon measures loaded, they are a bit discolored, the powder loads and shoots same as fresh from can.

BUT, I left a Redding loaded and the powder rotted its cheaper plastic, I think an acrylic.
I did not use the powder that had done that.
 
As long as the temperature doesn't dip below freezing, your powder will be fine for many years.
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Never heard of low temps being an issue, probably because few people reload when the temp is below freezing. High temps are known to increase the likelihood of the powder degrading. And ambient temp storages (below freezing in the winter, over 100 in the summer isn't a good thing, either.

Powder volume change due to changes in humidity usually isn't a big deal, either.

Having your powder hopper where it is exposed to direct sunlight IS a big deal, and not a good one.

Powder left in the hopper for days/weeks can react with the plastic of the hopper. Had it happen with one measure, ages ago, and while it is very uncommon with more modern plastics I don't risk it.

The biggest risk to leaving powder in the measure hopper is simply YOU. (or me,:rolleyes:)

Forgetting what it is, or even that its in there, and "getting started again" filling up the measure with a DIFFERENT powder before "remembering" that there is powder already in the measure is something we all scoff at, until we do it, (worst case), or manage to stop in time before "blending" with a different powder, and realize just how close we came.

The old rules are there with good, solid reasons.

ONE (and ONLY one) can of powder "on the bench" (open and in use) at a time. Return ALL unused powder back to the original container when you are finished reloading (I don't mean stopping for dinner, I mean when you know you're not going to go right back to loading after a short break).

CLEAN all the powder out of the measure by cycling it several times empty, and then visually check to be sure it IS empty.

Do essentially the same thing with primers. Sure, its a hassle, takes a few more minutes, but if it prevents you from using the wrong components, or wasting components (like accidently blended powder) even once its worth it.
 
I cannot think of one good reason to leave powder in the hopper when you’re done with a loading session.
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I can think of one very good reason NOT to leave powder in a hopper: some powders have a chemical reaction with the hopper tube and plastic internals in my RCBS Charge Master Combo. BE-86 did that, so I do not leave any powder in the machine anymore.

On a different note, I have several powders I transferred to other plastic containers when the original powder containers began to leak. WC872, 844 and Data Powder 2230-C (A-2460). None of those powders show any ill effects since rebottling in repurposed polyethylene containers.
 
( Leaving powder in a trickler or dispenser for a week sounds like a accident waiting to happen. )

totally agree. you may be young enough now, and never forget anything, but given time; you will ultimately forget what is in there.

powder is not an explosive; it requires pressure, but primers on the other hand go bang with the slightest spark. don't leave them where anything might happen. "anything"

remember mr. murphy rules that area.
 
Many years ago I had a Pacific powder measure that I used almost exclusively for Bullseye when doing large runs of .38 Spl. Usually it was either 2.7 gr. for wadcutter loads or 3.5 for semi-wadcutter loads. The hopper on that measure was literally full of Bullseye for sometimes weeks on end as I found time to charge cases and seat bullets. The hopper is discolored to a dingy almost opaque grey and one can see where the littles grains of powder imprinted into the plastic. I should replace the hopper but I haven't done a large batch of 38s in a long time. Last run was a bit over1,800 rounds and I haven't shot them all up yet. IIRC, that batch was with wadcutters and W231. I.m saving what little bullseye I have left to duplicate the original Frankford arsenal load of 230 gr. bullet over 5.0 gr. Bullseye.
Paul B.
 
If you follow proper chemistry labeling practices (always label a container of anything; you will remember incorrectly at some point), you will be fine for a period of a week. I have had powder in non-original plastic, metal screw-cap containers go bad, but over many moons, not a few days. I have a Dillon press that is dedicated to 45 Auto and seldom change the powder type in it, so it has stayed filled for long periods and has had no problems. It is evident the Dillon powder hopper is a powder-safe material. I do keep a Dillon protective cover over the machine between uses, and that keeps daylight out most of the time, though I don't know if that really matters to it much or not.

Dillonhelp said:
Smokeless gun powder can only gain or lose a tiny percentage of weight due to moisture. Just weight some charges to verify the desired weight is thrown before beginning to reload.As long as the temperature doesn't dip below freezing, your powder will be fine for many years.
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The 2013 Norma Reloading Manual, page 113, Diagram 4, shows gunpowder can gain up to around a percent and a quarter of water weight in high relative humidity (85-90%) as compared to the same powder stored in low relative humidity (25-30%). The low-humidity water weight depends on the powder formulation and can be anywhere from a quarter of a percent to a percent, so the final total high RH water weight could be about 1.5% to 2.5% in near 100% RH.

If powder does get below freezing, then it will last for centuries rather than just years. The U.S. military standards require ammunition to fire down to -65°F. This is the standard temperature at about 35,000 feet, so either they had aircraft in mind or combat on Mt. Everest. I don't know which. But the powder and primers hold up to those tests.
 
Recall Skeeter Skelton writing years ago that he left some powder-Unique (?) in a plastic hopper, when he loaded some rounds for a friend they were all duds, he looked at the hopper, saw it looked granulated, thought the powder and plastic had interracted in some way. After that he said he emptied the hopper after each reloading session.
 
That sure can happen. It just depends on what the plastic the hopper is made from. Dillon's doesn't seem to present a problem, but softer plastic (more plasticizer in it) in the mailing-tube style hoppers and in some other plastics can sure do it. Do you recall what powder measure Skelton used and how long he left the powder in it? I'll also note that Unique is double-base, and the presence of nitroglycerin in the nitrocellulose matrix may exacerbate the problem by wetting the plastic if any gets loose. The powder I've kept in the hopper longest is single-base.
 
Thanks Much

Thanks much for all of the insights.

I'm going to be comfortable keeping my dispensers loaded for a few days if I think I'll be coming back to load up again.

To all who are concerned about me mixing and matching: My components are stored in a closet ten feet from my bench and I always have one and ONLY one type of propellant, primer, bullet, and cartridge case on the bench and the original labeled containers are on the bench (except cartridge cases). I also have one and only one 'recipe' card on the bench. I can look at my labeled containers and be sure of what primers are on the tray, powder in the dispensers, etc. While my cartridge cases are mostly distinctive I do load both .38 special and .38+P and will only have one type of case on the bench.

Thanks again.

Larry
 
Smokeless powder will etch the plastic hopper of a powder measure and turn it dark and cloudy .
Best practice is to return powder to original cannister and wipe out hopper .
Way too many reloaders have left powder in the measure , come back later and forgotten what is in the measure or incorrectly identify what was in there and wind up with the wrong powder in a bunch of reloaded ammo .
Don't Leave powder in the measure ... empty it back into it's proper container !
Gary
 
I have had no problems with my dispensers. one Hornady and two x RCBS Light.

Two of them I just leave powder in them, as long as no reaction I don't think its any different than opening up an 8 lb jug and having 1-6 lbs in it as far as atmospheric exposure goes (each time you open up an 8 lb you recharge the air in there). Same amount of air.

I keep accurate logs of my velocity and have seen no drop off. It does get recharged as it gets low so there is a turnover. I do shoot a lot.

I keep the caps on the dispensers.

Shop temp is 60-75 deg and we have dry conditions.
 
Even though it’s not a good habit, I have left powder in the Lee red hoppers for extended periods without any etching or discoloration. I no longer do this due to accidentally adding a different powder not noticing I already had some in there. After that I always empty the hopper, one less bad habit broken.
 
At Dillon we tried a variety of plastics over the years. We finally figured out how to mold polycarbonate plastic, and the discoloring reactions due to residual solvents in the powders went away. You will still get some darkening from the graphite coating on some powders, but that wipes away.
 
I have a couple of cans from the 70s that still light fine.
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I have gone back to doing some pistol shooting and pulling out and using powders that date back to the 70s as well. Those were part 1 llb filled, some cans, some of the cardboard container type (seemed better than the cans but annoying lid setup)

All of them are clean with zero discoloration, no smell and they have shot just fine. Unique was more energetic than I had expected giving me over 1000 fps in a 45 Colt load that I was after 750 fps (granted its a 477 Walker so it has a LONG barrel!)

I am unusual in that I love the auto dispensers and could afford to have more than one (after one died, at least two and now 3)

I hate the Hornady , it does not store settings and you have to put setting into it to get to work. So I had one gun with one powder not used for anythi8ng other than that gun and I keep said powder in that dispenser. I know what the settings needed for it are.

I wanted a backup for the RCBS light so I got another one, all were on great sales.

I had a Lyman dispenser die twice on me, Lyman replaced the first time, not the 2nd

The other two I keep a 1 lb jug of whatever I am using in those next to the unit, so I have a ref as to what should be in there. Any questions I can compare the powder appearance (and yes I know that is not a given)

Is this a violation of the Cardinal edict of only one powder? Yes it is. I don't recommend it. I am not a hypocrite, it works for me but no one else has my brain nor how I like to do and go about things. Frankly my operation is a mix of my own experience, ideas from others. As an entity it is not always best practices but again, it works for me.

The issue with residue powder in the bottom is valid.

As noted, the powder appearance is not unique to any powder, some look and measure the same and are not. I accept that. The ones that may look like it are not the ones I have in the hoppers.

Worst case? I can do a trial load and confirm or deny the powder FPS with my logs of same.

I do think that its worth some thought as if you have an 8 lb jug, as it empties, more and more air is on top. You then disturb that air each time you open it up and dispense powder (I have 1 lb just for all of those and I just transfer into the 1 lb jugs but its still open above the remaining powder until I can get the rest into the 1 lbs jug.

Again worth some though, if you feed out of an 8 lb (or a 1 lb) and change the hopper powder, you then pour the hopper powder back in and it gets well aerated each pour.

Would this work for someone in 100 deg heat and high humidity? I don't know.

I do know that my powders have been stored at good temperatures, our humidity is low (more so in the house) and as Unclenick has made clear, there is not all that much transfer of humidity in or out of powder (or the affect is miner).

I think all of this is worth thought as you work out what works for yourself, borrow ideas from others that work, come up with some of your own.

As we all know, this is a risk. I shoot Mil Surplus rifles with unsupported case heads. That too is a risk. On the other hand, driving 10 miles to the range has set of risks.

You try to mitigate the risks in life (or should) and then go live it.
 
Smokeless powder will etch the plastic hopper of a powder measure and turn it dark and cloudy
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I can attest to that. My RCBS Uniflow hopper is almost completely black. It is still somewhat translucent, but barely.

This wasn't from leaving the propellant in the hopper. It's just from forty years of use. With the exception of maybe a half-dozen times I left the power sit overnight (to resume loading the next day), I always empty the hopper after the load session. So in my case, the discoloration is virtually just from the time I'm at the load bench.
 
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