How long can you leave powder in an closed powder measure on a press ( for me a Lee turret press) before it affects its performance/quality? I try to make sure it is no longer than 2 weekends. My press set-up is in my machine barn ( which I only heat when I need to work on my tractors/machinery ) and unfortunately it's snowing here in upstate N.Y. today. I'm concerned about the powder picking up moisture. Any suggestions/help would be greatly appreciated. Thank you for your time and expertise.
Leaving powder in powder measure
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500 Magnum Nut
Member
I'd just empty it. It will discolor the hopper, and the power will absorb moisture affecting the weights as you check your loads.
Dan Cash
Member
I leave powder in Dillon measures for prolonged preiods with no ill effects. In some cases, the measure is set up for a load such as .45ACP and is never emptied. Of course, the contents are distinctively marked. If you are concerned about moisture affecting the propellant place a small packet of deiscant or make up a small packet of rice in a paper towell and place it in with the powder.
Skip Sackett
US Veteran
1st: Temperature swings is going to cause moisture no matter what you store the powder in, closed container or open powder measure.
2nd: Are there any young folks around that can get at the powder more easily when it is in the measure? Even if they have been taught not to touch such things, temptation can be great for a child. No use putting it right before them.
3rd: What keeps you from putting it back? It takes like two seconds to remove the turret and the lid to the measure and dump it back in it's container.
4th: It will discolor the container. Not a big deal but, to some, aesthetics is everything.
All of that being said, I will leave powder in a measure only if I am going to continue loading that cartridge the next day or I am working up a load and will run more of that powder within a short amount of time, no more than a couple of days.
My reloading room can be locked so curious eyes could be kept out. Although all I have left at home is a 17 year old girl that doesn't show any interest in reloading!
2nd: Are there any young folks around that can get at the powder more easily when it is in the measure? Even if they have been taught not to touch such things, temptation can be great for a child. No use putting it right before them.
3rd: What keeps you from putting it back? It takes like two seconds to remove the turret and the lid to the measure and dump it back in it's container.
4th: It will discolor the container. Not a big deal but, to some, aesthetics is everything.
All of that being said, I will leave powder in a measure only if I am going to continue loading that cartridge the next day or I am working up a load and will run more of that powder within a short amount of time, no more than a couple of days.
My reloading room can be locked so curious eyes could be kept out. Although all I have left at home is a 17 year old girl that doesn't show any interest in reloading!
VAdoublegunner
Member
Hygroscopic qualities can be bad with some powders, less so with others. It can affect charge weight, but more importantly may lead to clumping, which I have experienced. If that happens, you may get a clump that partially to totally blocks the measure chamber so that you get erratic sub-charges. Besides poor accuracy it is a good way to get bullets stuck in your barrel then have to pull a bunch of loads. This is a "learn the hard way" example.
Also, I have noticed that leaving powder in my Hornady L-N-L hopper has caused it to swell. It is a hard poly type plastic rather than the type RCBS uses. Not a problem to fix, Hornady took care of it. But it is yet another reason to return powder to the can after you are finished.
Also, I have noticed that leaving powder in my Hornady L-N-L hopper has caused it to swell. It is a hard poly type plastic rather than the type RCBS uses. Not a problem to fix, Hornady took care of it. But it is yet another reason to return powder to the can after you are finished.
Empty it each time.
Raider
SWCA Member, Absent Comrade
I've left Unique and 231 in powder measure hoppers for years without ill effects. Depends on the humidity and temp its stored in. Probably best to put it back in the can though to be safe. YMMV.
Charlie
Charlie
Andy Griffith
Member
For myself at least, it isn't the humidity I worry about...
The danger is thinking it is one powder, when it is actually another!
If you only use one powder for everything, you have nothing to fear.
For me at least, it's best I put it back in the can.
The danger is thinking it is one powder, when it is actually another!
If you only use one powder for everything, you have nothing to fear.
For me at least, it's best I put it back in the can.
ncbengal
Member
Powder is light sensitive, too, and according to what I read continued exposure to daylight will degrade. Ever see smokeless powder sold in anything but opaque, black containers? Pour it back!
oldRoger
US Veteran
I am by no means a particularly neat sort guy as my wife can testify. But, I always empty it no later than the end of the day.
I can think of lots of reasons to empty it, many of you have mentioned some of them. I would add one, when you step away from the bench there is no guarantee when you will back, or if. Someone may be cleaning up after you.
I have been unable to come up with a single reason to leave powder in the hopper.
I can think of lots of reasons to empty it, many of you have mentioned some of them. I would add one, when you step away from the bench there is no guarantee when you will back, or if. Someone may be cleaning up after you.
I have been unable to come up with a single reason to leave powder in the hopper.
Nimrod44
Member
Do any of you guys remember the old Skeeter Skelton story about this? It seems he left powder in a hopper for a period of time then loaded some handgun rounds. This was when he was in some sort of law enforcement and responded to an accident with some injured livestock. Some of the stock needed to be destroyed so Skeeter began shooting only to have his cast bullets bounce off the skulls of several cows. He determined after further investigation the plastic in the hopper had an effect on the powder. This article was "Skeeter's Cow Killer Loads" if I remember correctly, very funny and a long time ago.
DougE
Member
I empty out my powder measure when I'm done with a reloading session and label it for the powder/charge I was using. May not be necessary but that's how I do things.
Vulcan Bob
Member
Some powders do affect the plastic part of the hopper and those I will not leave in. Unique and 2400 seem to be alright and I will leave them in. I use a piece of duct tape on the hopper to label the powder and charge weight thats in the hopper and leave the container of powder on the bench behind the measure as an additional reminder of whats in there. I have no children at home now and my man Cave is sorta dark as I use one of those wooden slat blinds on the window so no direct light hits the hopper.
The best, and certainly the safest practice,is to empty the measure into the powder's original container. By so doing, one does not have to worry about the effects of light, interaction with the measure's plastic reservoir over time, nor hygroscopic qualities of any powder.
I sometimes (well, often) leave my press set up (with powder in the hopper) for weeks if I'm doing a big run of a particular cartridge. Never had any ill effect that I could detect. I've never detected any discoloration of the plastic in the Lee powder measure, and if I have it set to throw a certain grain weight on Monday, it seems to throw that same weight when I get back to it on Thursday. (I do have an old RCBS uniflow that I bought used 30 years ago that had badly discolored plastic when I bought it.) As for the safety issues, I still only have one powder in use at a time, and I keep the container on the table until I'm finished with it, the scale is set for the weight I'm set up to throw, and when I've been away for a day or a week, I'll weigh the first one or two I throw. Continues to work for me!
Unless I am coming back to continue reloading very soon, I empty the measure. Leaving powder in the measure just introduces another variable that might cause an overcharge: "I think I left the measure full of Unique two weeks ago or was it Bullseye, oh, I'm pretty sure it was Unique." Also some powders can cause deterioration of the plastic hopper if left in for prolonged periods.
Rafter-S
Member
THAT is the reason I put powders back into their proper storage containers.
