Powder Evaporation

OverPressure · October 4, 2014, 02:45 PM

I purchased a Lees Adjustable Charge Bar for my Classic Lees Reloader.
I have the original scale , my goal was to cut .2 of a gr. off a 5.6 gr
charge of green dot. What i wound up doing was weighing a .71cc charge
adjusting my scale to 5.6 and then using the Micro Charger to atain my
5.4 gr. goal. I weighed quite a few charges of each load to make sure they
were consistant!!! Being a little sceptical i charged 3 5.6 loads last night
before i adjusted the Micro Charger.

Today i loaded 10 rds. at 5.4 gr , check intermitantly the weights and all was
fine. I decided to reweigh the 3 5.6 gr charges from the night before and
they were each all almost .2 of a gr light !!!

AND, NO!!! I didn't mistakenly charge the 3 cases at 5.4gr

Any experts out here?

higgite · October 4, 2014, 05:02 PM

Turn the cases that held the disappearing powder over and tap them on the bench top to see if any powder falls out.

If that doesn't solve the mystery of the missing powder, then I think the butler did it in the library.

OverPressure · October 4, 2014, 05:09 PM

Actually, i have a 5.6gr charge sitting in the scale, balanced right now and
i am going to see what happens over time!!!

Jim243 · October 4, 2014, 05:57 PM

I think it was Professor Plum in the kitchen with the pipe wrench (LOL).

If you have a high humility when loading powder and overnight the powder has had a chance to settle and dry a little, a one or two tenths change is not unusual for flake powder. It also will not make a substantial difference in how your round performs. You actually are loading by volume and not weight, the weight of the powder will change depending on the conditions and humidity in your room, but the volume will remain the same.

Jim

OverPressure · October 4, 2014, 06:12 PM

JIM423

I am North Of Seattle, That was kind of what i was thinking.

17T/$55K per M/W/C Honestly I would rather have my share sitting on my
gun rack!!!

snakeye · October 4, 2014, 09:36 PM

If you leave powder in the hopper overnight it will change with the temps and humidity...happens to me every time I am making a long run reloading and shut it down for the night and leave the powder in the hopper and start back up the next day.

Pathfinder45 · October 4, 2014, 10:32 PM

Yeah, with finer powders, some can hang up in the primer. What kind of scale do you use? But if you eliminate all other posibilities, it could be that such a small change may be attributable to a change in the position of the moon and sun; it affects the tides, a ya know....

Actually, a good old-fashioned balance scale measures weight by mass not gravitational pull. But if your using one of those chinese digital things, the real marvel is that you even trust the thing. Change the batteries, maybe? If you use a balance scale, make sure the agate bearings are clean of any dust, lint or whatever. As mentioned, the gremlin could be changes in humidity. If you just used factory ammo, you wouldn't even give it a thought. That two-tenths of a grain must keep you awake at night...... Here's the cure: Go buy a box of top-shelf factory ammo, dismantle, weigh, and carefully note every charge. It wouldn't surprise me at all if their ammo had well more than two-tenths of a grain variation. Sleep well and happy shooting.

James K · October 4, 2014, 10:43 PM

This is not really addressing the OP's problem, but to show the weird things that can happen to reloaders:

A friend had a problem with inconsistent powder charges, even though he is a meticulous person who weighs every charge when he wants accuracy and consistency. But the charges were NOT consistent. We talked about it and he showed me his loading setup, which was very neat, with a sturdy bench a slight distance from the wall.

We about went nuts until his heat pump kicked on and I noticed the scale pan moving. Sure enough, the vent was below his bench, and the air came up behind the bench, hit a bookshelf and blew outward, disturbing the scale and making it read low. He got one of those air deflectors for the vent and restored the accuracy of his rifles.

Jim

OverPressure · October 5, 2014, 11:34 AM

The scale i am using is a balance scale that comes with the
Lees Classic 4 die turret loader. The way i adjusted it was that
i assumed that .71cc of powder was 5.6 grains. This scale allowes
me to adjust it accordingly to enable this method. I then adjust the
Lees Microcharger to give me .2 of a gr. less powder.

The way i checked myself was to weigh a dozen or so charges of
powder at 5.6 gr. Once i was satisfied the Lees autodisk was
giving me a consistant charge, i swaped the disk with the micro
charger and dialed it in until i got a weight .2 lighter or 5.4gr.

The goal is to slow the bullet down about 40fps. So i feel confident
that i am close to the desired reduction, even though i don't really
know for sure the weight is accurate.

What i have is a consistant 880fps to 900fps accurate rd that i want
to slow down a bit.

Anyway, to make a short story longer i had 3 charged 5.6gr cases sitting on
the bench all night and weighed them the next day and they were all almost
.2 light.

After reading some boggy man comments yesterday i put 5.6gr of powder, balanced it in the scale, put it where it wouldn't be disturbed and it has
sat for 20 hrs. It has gained about a half a tenth in weight.

This has done nothing but confuse me more. I am generally not overly religious
but if i was there is plenty of room for a shooting god!!!

THIS GOD WOULD BE A CHRISTIAN GOD MIND YOU!!!

Lost Sheep · October 5, 2014, 02:59 PM

Quote:

Originally Posted by OverPressure

Powder Evaporation
I purchased a Lees Adjustable Charge Bar for my Classic Lees Reloader.
I have the original scale , my goal was to cut .2 of a gr. off a 5.6 gr
charge of green dot. What i wound up doing was weighing a .71cc charge
adjusting my scale to 5.6 and then using the Micro Charger to atain my
5.4 gr. goal. I weighed quite a few charges of each load to make sure they
were consistant!!! Being a little sceptical i charged 3 5.6 loads last night
before i adjusted the Micro Charger.

Today i loaded 10 rds. at 5.4 gr , check intermitantly the weights and all was
fine. I decided to reweigh the 3 5.6 gr charges from the night before and
they were each all almost .2 of a gr light !!!

AND, NO!!! I didn't mistakenly charge the 3 cases at 5.4gr

Any experts out here?

The underlining above is mine because that (as I interpret your post) may be where your procedure is introducing a .2 grain mistake. (Note, I write "mistake" and not "error".)

If you adjusted your scale to show 5.6 grains coming out of your 0.71cc cavity, that would be wrong. Lee dippers and Auto-Disk cavities are widely known to drop slightly lighter charges than published in Lee's charts. 0.2 grains lighter is not unexpected.

If, the next morning, you zeroed your scale with an empty pan, you could very well have re-introduced the .2 grain difference.

If I am wrong about my reading of your description, ignore this post.

If I am even partially right, heed this:

ALWAYS zero your scale to zero with an empty pan. (Then, if you have any check weight(s) weigh it(them) to check.)

If you do that, weigh the charges coming out of your measure that are giving your 880 to 900 fps, subtract .2 grains from that weight, whatever it is.

Then, you load up a few rounds with the reduced charge weight and see what velocity you get.

Good luck.

Lost Sheep

Pathfinder45 · October 5, 2014, 09:00 PM

Yeah, zero the empty pan and see if it changes overnight. So far, I'm thinking changes in humidity might be the culprit.

OverPressure · October 11, 2014, 08:51 PM

I don't have the answer as to the three charged cases that all weighed in
at 5.4 gr after being charged by the .71 cc lees autodisk die. I had dialed
in the 5.6 gr on the lees scale the day before and saved 3 charges in case
i wanted to retest the scale while i was working on a process to dial
in the lees microcharger.

Last week i put 5.6gr on the lees scale set it aside and IT AIN'T MOVED
MORE THAN A - - - - HAIR IN A WEEK!!!

Sorry about all the drama!!!

Longshot4 · October 12, 2014, 07:41 AM

My 2 cents is. powder is dry. there are ways to measure moisture content. It seams to me more moisture would increase the weight of powder. Powder would draw moisture out of the air if the powder moisture content is less than the moisture in the air. If the powder contains a solvent... it could be evaporating. Get the tools to do the measurable or let it go.

Airman Basic · October 12, 2014, 07:53 AM

Quote:

If you have a high humility when loading powder

My wife says I ain't got enough of that anytime

October 4, 2014, 02:45 PM	#1
OverPressure Member Join Date: March 11, 2013 Location: Langley WA Posts: 66	Powder Evaporation I purchased a Lees Adjustable Charge Bar for my Classic Lees Reloader. I have the original scale , my goal was to cut .2 of a gr. off a 5.6 gr charge of green dot. What i wound up doing was weighing a .71cc charge adjusting my scale to 5.6 and then using the Micro Charger to atain my 5.4 gr. goal. I weighed quite a few charges of each load to make sure they were consistant!!! Being a little sceptical i charged 3 5.6 loads last night before i adjusted the Micro Charger. Today i loaded 10 rds. at 5.4 gr , check intermitantly the weights and all was fine. I decided to reweigh the 3 5.6 gr charges from the night before and they were each all almost .2 of a gr light !!! AND, NO!!! I didn't mistakenly charge the 3 cases at 5.4gr Any experts out here?

October 4, 2014, 05:09 PM	#3
OverPressure Member Join Date: March 11, 2013 Location: Langley WA Posts: 66	Evaporation Actually, i have a 5.6gr charge sitting in the scale, balanced right now and i am going to see what happens over time!!!

October 4, 2014, 05:57 PM	#4
Jim243 Senior Member Join Date: January 5, 2009 Location: Just off Route 66 Posts: 5,067	I think it was Professor Plum in the kitchen with the pipe wrench (LOL). If you have a high humility when loading powder and overnight the powder has had a chance to settle and dry a little, a one or two tenths change is not unusual for flake powder. It also will not make a substantial difference in how your round performs. You actually are loading by volume and not weight, the weight of the powder will change depending on the conditions and humidity in your room, but the volume will remain the same. Jim __________________ Si vis pacem, para bellum Last edited by Jim243; October 4, 2014 at 06:05 PM.

October 4, 2014, 06:12 PM	#5
OverPressure Member Join Date: March 11, 2013 Location: Langley WA Posts: 66	Moisture Content JIM423 I am North Of Seattle, That was kind of what i was thinking. 17T/$55K per M/W/C Honestly I would rather have my share sitting on my gun rack!!!

October 5, 2014, 11:34 AM	#9
OverPressure Member Join Date: March 11, 2013 Location: Langley WA Posts: 66	Clarification The scale i am using is a balance scale that comes with the Lees Classic 4 die turret loader. The way i adjusted it was that i assumed that .71cc of powder was 5.6 grains. This scale allowes me to adjust it accordingly to enable this method. I then adjust the Lees Microcharger to give me .2 of a gr. less powder. The way i checked myself was to weigh a dozen or so charges of powder at 5.6 gr. Once i was satisfied the Lees autodisk was giving me a consistant charge, i swaped the disk with the micro charger and dialed it in until i got a weight .2 lighter or 5.4gr. The goal is to slow the bullet down about 40fps. So i feel confident that i am close to the desired reduction, even though i don't really know for sure the weight is accurate. What i have is a consistant 880fps to 900fps accurate rd that i want to slow down a bit. Anyway, to make a short story longer i had 3 charged 5.6gr cases sitting on the bench all night and weighed them the next day and they were all almost .2 light. After reading some boggy man comments yesterday i put 5.6gr of powder, balanced it in the scale, put it where it wouldn't be disturbed and it has sat for 20 hrs. It has gained about a half a tenth in weight. This has done nothing but confuse me more. I am generally not overly religious but if i was there is plenty of room for a shooting god!!! THIS GOD WOULD BE A CHRISTIAN GOD MIND YOU!!!

October 4, 2014, 05:02 PM	#2
higgite Senior Member Join Date: October 21, 2010 Posts: 1,025	Turn the cases that held the disappearing powder over and tap them on the bench top to see if any powder falls out. If that doesn't solve the mystery of the missing powder, then I think the butler did it in the library.

October 4, 2014, 09:36 PM	#6
snakeye Senior Member Join Date: July 5, 2013 Location: Arlington, TX Posts: 127	If you leave powder in the hopper overnight it will change with the temps and humidity...happens to me every time I am making a long run reloading and shut it down for the night and leave the powder in the hopper and start back up the next day.

October 4, 2014, 10:32 PM	#7
Pathfinder45 Senior Member Join Date: January 7, 2008 Posts: 3,224	Yeah, with finer powders, some can hang up in the primer. What kind of scale do you use? But if you eliminate all other posibilities, it could be that such a small change may be attributable to a change in the position of the moon and sun; it affects the tides, a ya know.... Actually, a good old-fashioned balance scale measures weight by mass not gravitational pull. But if your using one of those chinese digital things, the real marvel is that you even trust the thing. Change the batteries, maybe? If you use a balance scale, make sure the agate bearings are clean of any dust, lint or whatever. As mentioned, the gremlin could be changes in humidity. If you just used factory ammo, you wouldn't even give it a thought. That two-tenths of a grain must keep you awake at night...... Here's the cure: Go buy a box of top-shelf factory ammo, dismantle, weigh, and carefully note every charge. It wouldn't surprise me at all if their ammo had well more than two-tenths of a grain variation. Sleep well and happy shooting.

October 4, 2014, 10:43 PM	#8
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	This is not really addressing the OP's problem, but to show the weird things that can happen to reloaders: A friend had a problem with inconsistent powder charges, even though he is a meticulous person who weighs every charge when he wants accuracy and consistency. But the charges were NOT consistent. We talked about it and he showed me his loading setup, which was very neat, with a sturdy bench a slight distance from the wall. We about went nuts until his heat pump kicked on and I noticed the scale pan moving. Sure enough, the vent was below his bench, and the air came up behind the bench, hit a bookshelf and blew outward, disturbing the scale and making it read low. He got one of those air deflectors for the vent and restored the accuracy of his rifles. Jim

October 5, 2014, 09:00 PM	#11
Pathfinder45 Senior Member Join Date: January 7, 2008 Posts: 3,224	Yeah, zero the empty pan and see if it changes overnight. So far, I'm thinking changes in humidity might be the culprit.

October 11, 2014, 08:51 PM	#12
OverPressure Member Join Date: March 11, 2013 Location: Langley WA Posts: 66	Evaporation I don't have the answer as to the three charged cases that all weighed in at 5.4 gr after being charged by the .71 cc lees autodisk die. I had dialed in the 5.6 gr on the lees scale the day before and saved 3 charges in case i wanted to retest the scale while i was working on a process to dial in the lees microcharger. Last week i put 5.6gr on the lees scale set it aside and IT AIN'T MOVED MORE THAN A - - - - HAIR IN A WEEK!!! Sorry about all the drama!!!

October 12, 2014, 07:41 AM	#13
Longshot4 Senior Member Join Date: February 22, 2014 Posts: 868	My 2 cents is. powder is dry. there are ways to measure moisture content. It seams to me more moisture would increase the weight of powder. Powder would draw moisture out of the air if the powder moisture content is less than the moisture in the air. If the powder contains a solvent... it could be evaporating. Get the tools to do the measurable or let it go.