Varget gets slower

[308BAR]

That doesnt explain his powder getting slower as he works thru the jug

New powder will have more moisture content, as you work through a keg, open and closing the lid moisture escapes and the powder equalizes with the humidity of the room, also as the level of powder lessens in a jug there is more room for air in the container to for power to release moisture. New powder will be faster than powder that is dryer.

 

[Dusty Stevens]

New powder will have more moisture content, as you work through a keg, open and closing the lid moisture escapes and the powder equalizes with the humidity of the room, also as the level of powder lessens in a jug there is more room for air in the container to for power to release moisture. New powder will be faster than powder that is dryer.

You should weigh a charge from a new jug, then put it in a glass vial weighed with a sho nuff good scale then weigh again in a year.

 

[dolek]

You should weigh a charge from a new jug, then put it in a glass vial weighed with a sho nuff good scale then weigh again in a year.

Have you done this ? If so what did you find ?

 

[GSPV]

Powder does not absorb water, it adsorbs it. Therefore the volume (size) doesnt increase but the weight does.

FWIW, my experience has been that the volume of a given weight of powder actually increases as it *dries* out. Looking at it from the other direction, you get less powder per unit volume as it dries out.

 

[redneckbmxer24]

I've emptied more than a few jugs of Varget and have never experienced this. Varget has also been the most consistent powder lot to lot that I've used. I've had some but it's incredibly small.

I agree with the thought that it may be collecting moisture and increasing in weight but not volume and that's what you're seeing. I'd say you have a humidity problem if this is happening and invest in some dehumidifiers.

 

[Dusty Stevens]

Have you done this ? If so what did you find ?

I found that it got heavier. Then studied up on adsorption and found out why. Not absorption im not mis-spelling it.

 

[rwj]

Perhaps a chemist/thermodynamicist will add to this thread... but I’m thinking that any water (liquid and/or vapor) will quickly flash to steam during ignition thereby increasing chamber pressure and muzzle velocity... but perhaps its presence poses combustion limitations?

 

[Dusty Stevens]

Perhaps a chemist/thermodynamicist will add to this thread... but I’m thinking that any water (liquid and/or vapor) will quickly flash to steam during ignition thereby increasing chamber pressure and muzzle velocity... but perhaps its presence poses combustion limitations?

Thats true but it doesnt help when youre weighing down to the fraction of kernel before you ever light it off

 

[joshb]

Bump.

 

[308BAR]

I found that it got heavier. Then studied up on adsorption and found out why. Not absorption im not mis-spelling it.

The amount of adsorbtion I would surmise is really dependant on the environment. What we don't know don't know is where the OP and everyone location is and environment the powder is stored in.

So the question is did you see a decrease in velocity or increase in velocity with your powder adsorbtion you experience? Interesting stuff.

The only thing I notice with the Varget I shots is that with temperature increase I see anywhere from a 25-50fps increase in velocity over 10°C - 15°C change.

 

[Dusty Stevens]

The amount of adsorbtion I would surmise is really dependant on the environment. What we don't know don't know is where the OP and everyone location is and environment the powder is stored in.

So the question is did you see a decrease in velocity or increase in velocity with your powder adsorbtion you experience? Interesting stuff.

The only thing I notice with the Varget I shots is that with temperature increase I see anywhere from a 25-50fps increase in velocity over 10°C - 15°C change.

No idea on velocity. Never concerned me much. The powder is in a sealed glass vial and once it got heavier then it started changing thru the year. This is not a change you can see on a gem pro or chargemaster scale but if youre weighing charges on a lab scale you will have less powder in your cases on a humid day and that equates to less velocity

 

[Beau]

No, but I have had the barrel get slower as the round count down the tube gets higher.

They most certainly do. David Tubb has even commented on it.
I only load by volume. I never change the setting. By the end of a jug, I need several more minutes elevation at 600. Put on a new barrel - Surprise! Gotta take those clicks off again. Same loads, never varies.