What affect does humidity have while reloading.

[mjmagee67]

So my question would be.....If your powder absorbed water out of the air would it increase or decrease velocity? I submit to the peanut gallery that if your powder absorbed a grain or 2 of water it might increase velocity. When you have a liquid and convert it to a gas you get a huge increase in volume. So "damp" powder may have an increased gas volume over the dry powder for similar weights of powder. Just a thought..... 

[synchronicity]

The goal is consistency.   Every round identical to every other round.

Any change in any direction is bad.

And then there are those who embrace chaos, and sometimes they don't shoot so bad either.

[Service Desk]

Anecdotal considerations around the fire bucket at my local range support the theory that a higher moisture content actually slows the burn and produces lower velocities. About  a combined 250 years of reloading experience among 8 or so seats.

 

[9x45]

Just a little too humid to load today, think I'll wait till it drops down to 20%RH.......

[Steve RA]

Looks like you are close to the average of 25%.  I'd say "go for it" !    

[Steve RA]

Sort of Interesting:

 

This antique bottle of gunpowder sits in the Ballistic Laboratory outside the office of our Chief Technical Information Representative at the Alliant Techsystems plant in Kenvil, New Jersey. The Powder was manufactured at this same plant in 1899, when the company was known as Laflin and Rand Powder Company. That was 13 years before it became the Hercules Powder Company, and 97 years before it became Alliant Powders. This nearly-century-old, double-based gunpowder is stored under distilled water to protect it from deterioration, because stabilizers for long-term storage were not introduced before about *1910. Periodically our ballistic engineers dry a small amount and test fire it in a 12 gauge test load. Amazingly, it still performs almost to its original specifications. The jar of powder is there to remind us not only of the long and proud tradition of our company, but of the commitment we have to consistency. We never forget that reloaders must be able to count on consistent and repeatable performance from their powders - lot after lot, year after year. In an age of fads and constant change when it comes to powder there's something to be said for the absolute, unchanging predictability of yesterday's and today's propellants from Alliant.

[peterthefish]

So my question would be.....If your powder absorbed water out of the air would it increase or decrease velocity? I submit to the peanut gallery that if your powder absorbed a grain or 2 of water it might increase velocity. When you have a liquid and convert it to a gas you get a huge increase in volume. So "damp" powder may have an increased gas volume over the dry powder for similar weights of powder. Just a thought..... 

It would decrease velocity. Water expands when it turns into a gas, but not nearly as much as smokeless powder. Damp powder is bulkier due to the absorbed water, so you're getting less per charge.

[mjmagee67]

6 hours ago, peterthefish said:

 

It would decrease velocity. Water expands when it turns into a gas, but not nearly as much as smokeless powder. Damp powder is bulkier due to the absorbed water, so you're getting less per charge.

 

Are you sure about that? Adding water to some explosive mixtures makes them much more powerful.  I would love to hear a couple of gun powder engineers weigh in on it, hell or even a few chemist who know rapid oxidation chemistry. 

[rowdyb]

25% humidity.. hahaha. that's funny. with a dehumidifier running powered on 24/7 now in the garage I keep it at 55% and it feels tolerable. before it was anywhere from 65-90% humidity in the garage.

[9x45]

It's so dry here that sometimes the rain doesn't even reach the ground. This was outside during a pending storm in the mountains. 

[R1_Demon]

On 8/24/2017 at 6:55 PM, GrumpyOne said:

Why are you heating hot water? 

 

LOL!  I don't know. Maybe to make sure it stays hot?  LOL! 

[9x45]

OK, humidity is just perfect now. Time to reload.

 

 

[9x45]

Dang, too late. RH dropped again, inside the house

 

 

[rowdyb]

i'm happy to keep it at 50% in the garage with my dehumidifier

[PhillySoldier]

In regards to this; does everyone re-bottle their powder and clean out there hopper after each session or just leave the powder in the hopper?

[MemphisMechanic]

39 minutes ago, PhillySoldier said:

In regards to this; does everyone re-bottle their powder and clean out there hopper after each session or just leave the powder in the hopper?

 

I load in Memphis. Same high humidity as @rowdyb. I never empty my hopper. I leave my press still full of primers, and partially loaded rounds. I just resume pulling the handle and checking cases for powder.

 

My ammo has never given me the slightest hint of an issue. Hell, if powder absorbs water, then ALL of my powder I’ve ever loaded has absorbed pretty much the same amount.

 

This is a case of bored gun guys sitting at computers and inventing things to worry about. Real world experience doesn’t bear it out.

[PhillySoldier]

I do the same as far as leaving powder and primers in the station. But I do start each session with calibrating my scale and weighing the charges and do see the weight change day by day as others have pointed out. I was wondering if perhaps re-bottling the powder resolves the problem. Or perhaps something simple such as sealing the hopper better. 

[lgh]

2 hours ago, PhillySoldier said:

In regards to this; does everyone re-bottle their powder and clean out there hopper after each session or just leave the powder in the hopper? 

I usually might leave powder in the hopper for a day or two. But I know over the years I've left it in for more than a week. Since I recheck the thrown wt before any reloading session, I know the powder does settle and the charge increases but other than that I have noticed no ill effects. Well, the hopper gets yellow if that counts.

[sweatpants]

4 hours ago, PhillySoldier said:

In regards to this; does everyone re-bottle their powder and clean out there hopper after each session or just leave the powder in the hopper?

 

I leave everything in the hopper regardless of atmospheric conditions.  But I also sanity check powder drops every session and go through my loaded ammo within a month.  With the sweltering conditions (and sometimes humidity) I've considered just calling it quits and moving my setup indoors.

[rowdyb]

Titegroup would clump in my hopper in two weeks. No matter what was going on. Sport Pistol doesn't and I quite often do like MM said and just leave things in mid-reloading and come back to them at my leisure and I never even think about emptying the hopper. The gauge on the wall has my garage constantly between 40 and 60% humidity.

[synchronicity]

I keep my powder in a sealed container except for the portion that I am measuring loads out of.

 

When I am done loading, the powder goes back into a sealed factory container.

 

I aim for the maximum temperature  stability that I can provide.

 

Primers are stored in factory packages in a similar environment to the powder.

[Roadhog]

Caution here loaders: Get your humidity levels way down low increases the potential for static electricity. Use proper precauction to decharge before handling components, especially primers. There's my 2 cents.

[Bulldog317]

Here in MD it gets pretty Humid in the summer.

If I'm going to skip more than 2 or 3 day's I unload the hopper, and place the powder back in it's container, and put some dryer sheets in the hopper.

My press sits right in front of two basement windows, so if I do leave the powder for a day or two I do cover the hopper with a Pringles can to keep the direct  sunlight  off of it.

I also run a dehumidifier 24/7 and was told by other re-loaders when I started as a rule of thumb...if I'm comfortable sitting in the room the powder is comfortable.

[Alderleet]

On 7/25/2012 at 5:37 PM, Jaxshooter said:

I live in Florida and the heat and humidity is why I have a gun / reloading room in the house. I would not reload in the summer if I had to do it in the garage..

 

Thisx10,000. I live north of the line, and my garage stays at a brisk 100+ with 50%+ humidity.

 

My inlaws can deal with sharing a room with reloading presses, while they visit. Haha.

[PhillySoldier]

I went to reload the other day. Started the session by letting the scale warm up, calibrating and weighing the powder charges. I use the armanov clickable dial on my hopper and had to lower it 6 clicks just to get back to my weight charge. I always feel weird about making adjustments due to humidity changes. It just doesnt seem consistent to me.