[bobinwa]

I assume the drop weight of powder can be affected by humidity (as well as static) but does it vary as much 1 grain? I was getting 16.6 g of Clays powder (Canadian) a few months ago and now it's only about 15.6 with the same bushing. I live in the Seattle area so the humidity is much lower right now than in the spring. I load on a Spolar Gold. I've cleaned the bar and checked the bushing and all seems good. Do you folks have the same problem and do you just change bushings to get back to the weight you want for the conditions of the day?

thanks in advance,
bob

 

[SteveS1965]

Hey Bob is it a new jug of powder or the same one you were getting 16.6 with

 

[bobinwa]

Steve, yes it is the same jug and I forgot to mention I keep a dryer sheet in the jug, and I pour the powder back into the jug at the end of loading session. It's around half full.

 

[Nebs]

How much exposure does your powder get to the air? Do you either keep it sealed in its container or in a hopper with a lid on it? I'm trying gauge how much opportunity there is for the powder to gain and loose weight or add/shed bulk based on changes in humidity.

 

[mat!_SW]

Keep a consistent humidity in your reloading room. Use a dehumidifier. If you're leaving powder in your bottle, weigh and throw back ten or so drops. Especially if you're leaving it for more than a day

 

[shotgunner50]

Controlled humidity will give you more consistent powder drops with any powder but some powders are affected more than others from low humidity.

 

[Curly N]

Back in the day, and maybe still, Once a BenchRest shooter found his load with his powder measure, he never weighed the load again until he changed powder lots and maybe not then. Those guys are a bunch more finicky than any shotgun shooter.

 

[henrydog]

Temperature. Hot means light drops cold is heavy. It come down to air density. Ya I know what I am talking about, i was born it the hell hole formally known as Seattle and have a earth science degree. Humidity does play a factor but even on the driest day in pudget sound the humidity is nothing like the midwest or southeast part of the country.

 

[bobinwa]

How much exposure does your powder get to the air? Do you either keep it sealed in its container or in a hopper with a lid on it? I'm trying gauge how much opportunity there is for the powder to gain and loose weight or add/shed bulk based on changes in humidity.

News, I keep the powder in the original 8 lb keg until ready to load the transfer some into the bottle which has a lid. I put any remainder back in the keg at the end of the day.

 

[bobinwa]

Temperature. Hot means light drops cold is heavy. It come down to air density. Ya I know what I am talking about, i was born it the hell hole formally known as Seattle and have a earth science degree. Humidity does play a factor but even on the driest day in pudget sound the humidity is nothing like the midwest or southeast part of the country.

Temperature does vary in the garage from 45-50 in colder months to 65-75 in warmer. That could be it. Do you go with the difference in powder throw or change bushings to get the same weight?

 

[Ray Ertel]

From way back I remember someone saying if you have a large keg, 8lb. etc. to shake up the powder before each use. I guess if it sits for a while supposedly some things in powder separate. Shaking it up mixes everything up again. Dont know if that is true or not but cant hurt.

 

[henrydog]

Temperature does vary in the garage from 45-50 in colder months to 65-75 in warmer. That could be it. Do you go with the difference in powder throw or change bushings to get the same weight?

I load in a pole building and have the same temp swings I drop a bushing size for the winter

 

[skeeljc]

The variation you stated is not normal. Unless you leave your powder in an open container exposed to the air humidity will not be a factor.

You might explain exactly how you measure your powder drops.

The most accurate way to measure powder drop is to remove the shell and shell holder just before the powder is dropped and weigh them (zero the tare) then remove them after the powder is dropped and weigh the charge. Do this during normal loading with the loader full of shells.

An alternate method is to use a capture device like P/W sells to capture the charge during loading. The capture device can be set in an empty hull and set on your digital scale to zero the tare weight.

Avoid transferring the powder drop from one container to another.

 

[bobinwa]

The variation you stated is not normal. Unless you leave your powder in an open container exposed to the air humidity will not be a factor.

You might explain exactly how you measure your powder drops.

The most accurate way to measure powder drop is to remove the shell and shell holder just before the powder is dropped and weigh them (zero the tare) then remove them after the powder is dropped and weigh the charge. Do this during normal loading with the loader full of shells.

An alternate method is to use a capture device like P/W sells to capture the charge during loading. The capture device can be set in an empty hull and set on your digital scale to zero the tare weight.

Avoid transferring the powder drop from one container to another.

Jim, I will try that. My method has just been to pull the shell and shell holder after the powder drops and dump the powder into the measuring cup on my Lyman digital scale.

 

[Trapduster]

Jim, I will try that. My method has just been to pull the shell and shell holder after the powder drops and dump the powder into the measuring cup on my Lyman digital scale.

 

[Trapduster]

It is the tem I load with a spolar in the garage and I have to change bushings when it changes quite a bit.

 

[ernscott]

Could the humidity be holding some of the powder in the hull after you dump the powder into the scale pan. Look in the hull with a flashlight to be sure. I do the same method and give the hull a couple of taps with a brass pin to shake all the powder into the pan. Regards ES

 

[Nebs]

News, I keep the powder in the original 8 lb keg until ready to load the transfer some into the bottle which has a lid. I put any remainder back in the keg at the end of the day.

Then I think it unlikely changes in humidity are causing your issue. I agree with Jim Skeel that making sure you are measuring your powder so you get consistent results is key.

 

[muggs410]

When I bought Red Dot and Unique in 15 or 16 pound cardboard kegs, I would notice a weight change from top to bottom of keg. There was probably a greater change with the Unique.

An experienced reloader friend noticed the same and observed that when you opened a new keg you could detect a solvent odor that reduced as the powder was used. He concluded the solvent producing that odor evaporated as the keg was used and that loss resulted in the loss of weight.

 

[Jet setter]

I assume the drop weight of powder can be affected by humidity (as well as static) but does it vary as much 1 grain? I was getting 16.6 g of Clays powder (Canadian) a few months ago and now it's only about 15.6 with the same bushing. I live in the Seattle area so the humidity is much lower right now than in the spring. I load on a Spolar Gold. I've cleaned the bar and checked the bushing and all seems good. Do you folks have the same problem and do you just change bushings to get back to the weight you want for the conditions of the day?

thanks in advance,
bob

Hi Bob,

I chalk it up to the joys of reloading. My reloading is done in my garage. When I load, I fill the powder hopper and I cycle my press a few times to get the powder settled. I always measure drops before every loading session and take random measurements every dozen or so shells.

On hot and muggy days, I get bigger fluctuations in powder drops. Rainy days give me the same results. I just change to the appropriate bushing to give me the correct weighed drop I need and get on with loading. It can change from day to day and is very climate dependent. For me, I tend to avoid loading when it is raining or humid. That saves me from having to constantly make bushing changes.