answer me this

That agging capability is affected by high or low humidity, I have no clue.
I can say that moisture in powder does have an affect. For those that
measure powder, it may swell the kernels and less powder is charged
at a given setting , or Maybe the moisture content dampens the fire in the boiler, for those that weigh. I cannot load 20 shells , shoot 10 on a dry day
and 10 in the rain and find a difference. I can however find a difference
in powder that has been intensionally dampened. This I did a few years
ago. Powder placed outside in the open air over night, in july and powder
put in a refridgerator shows a major difference in velocity. Admittedly,this is
an extreme that few will see in normal loading. The powder was 133
lot 820-04. The load was 29 grains and 10 loads of each were placed
in glass vials. They were all fired from the same 10 cases. The powder
left under the stars lost 160 fps avg as compared to the dry. The
moisture loaded powder did not seem to bulk higher in the case than
the dry. This was a very limited experiment, and no doub't is flawed.
It does show that some effect is possible. Understand that this has only
to do with moisture content in powder and not Relative Humidity.
That some leave there measures open all day or store powder with
loose lids in higher humidity, who is to say. Everyone may not be affected in the same way


Bob,

Every powder manufacturer that I've talked to has told me that powder is not hygroscopic and therefore cannot absorb moisture from the air. Evidence of this can be found in your own experiment when you said that both the powders laid outside and the powder left in your fridge filled up the case to the same level. So if moisture can't affect the powder physically, then the interior ballistics (combustion properties) must not be affected.

More than likely, the difference in velocity you saw came from temperature differences (65,70 degrees? vs. 41 degrees). This would certainly change the combustion levels and there are many books that back this up.

We've talked about this before and I know you have seen vastly different qualities of powder where you live compared to where I live. I do however have the one range I talked to you about that is right next to a swamp and is pretty humid. At that match, I have seen a load stay good all day and thought about the possibility of humidity doing something to the load there. But after shooting there this year in a rain storm (which raised the humidity to 100%, I found the load could be "chased" again by loading to my temp chart which then sent me on a quest to prove the humidity hypothesis. Thus far, it has not been singled out as a factor distinguishable from temperature.
 
This thread has been on the site now for over a week now. Since there has been no scientific data provided by those "believers" in humidity in that amount of time, are we to understand that there is none?

The burden of proof is in your hands. Are you just going to ignore the question now? Perhaps the fellows who can prove your moisture theories with scientific fact are out shooting and not here at all? Or perhaps there just isn't any scientific proof that humidity alone can make your tune go away. A quote from a ballistics book? An internet study? Something at all besides heresay? In my own studies, the only thing I could find that even hinted at the humidity changing anything was "that it produced such small quantities of change that it could be ignored."
 
Goodgrouper,
I gave you some data, that came fro Jim Borden, and so did Bob, his own. Also, Mike R. said in his booK that it adsorbs. Maybe you didn't ask the powder mfgs. the right question. Have you ever stuck your hand in a pile of sand that has been sitting outside for some time and notice that it was damp even thouugh the ground around it was dry? Do the individual pieces of quartz absorb moisture?
 
Goodgrouper

My humidity test was a rough and far more extreme than what anyone will
have in normal loading. I will not claim any facts here, just what I saw
on my chronograph. The powder temp was very close to the same outside
as inside where it was weighed. This was a very warm summer night,
and everything was soaked with dew in the AM. If anything, the powder from the refriderator could have been cooler and given a lower vel.Extruded
powders are porous and hold air, be that dry or wet. It need not be hydroscopic,. or show a change in size. I recall discussion on Moly, where it is believed that moly
did not just reduce pressure, but moisture played its hand, thereby
reducing velocity.
 
Goodgrouper,
I gave you some data, that came fro Jim Borden, and so did Bob, his own. Also, Mike R. said in his booK that it adsorbs. Maybe you didn't ask the powder mfgs. the right question. Have you ever stuck your hand in a pile of sand that has been sitting outside for some time and notice that it was damp even thouugh the ground around it was dry? Do the individual pieces of quartz absorb moisture?

Forgive me Boyd, but the data you gave was nothing but heresay from what I could gather. Granted, I couldn't really make out what you where trying to say about Jim's tests but I guessed that it was supposed to be in favor of humidity theory. Bob's tests made sense but I don't think they isolated pure data about humidity as temperatures were also in the mix and I have no doubt that temps make a difference. I asked you to sum up what Rattigan said and you didn't until just now. So there is still not any supporting data that would hold up in court. And my question to powder companies was simply, "is powder Hygroscopic and will varying humidity affect charges thrown by volume. I don't know how I could have made it any simpler.

DOn't know what sand has to do with gun powder either.:confused:
 
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What does sand have to do with powder

My thought is, it may hold it without absorbing it. Just as sand does.
Where is Henry when you need him ?
 
Sorry I was not more clear. Anyone else have trouble understanding?

Heresay? Are we in court? Do you doubt my veracity? Why don't you simply collect your copy of Mike's book and read the section I referred to, call Jim Borden, and then report back?
 
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At one time, with a 222mag bench gun, I was hell bent to use 748Win
ball powder. Now Ball powder is for the most part as un porous as any
powder made. The flattened balls of powder are added to otherwise
round balls of powder to improve ignition( can't tell you the scource of that).
because it lacks porosity, which aids ignition. I eventually gave up on that
because it clung together in my measure like sugar on a damp day. Had
I not allowed the powder to remain in the measure over night would have helped a lot. Ball powder is a laquer/plastic ball and I doub't that it
actually absorbs it, but seems it may keep it around for awhile
 
Heresay? Are we in court? Do you doubt my veracity? Why don't you simply collect your copy of Mike's book and read the section I referred to, call Jim Borden, and then report back?

No, Boyd, we're not it court. But I'm trying to get to the bottom of an interesting topic that thus far, has not seen any scientific fact supporting the humidity effect. Jim Borden's test was just like mine and Bob's. Not completely scientific and not totally controlled. I'm afraid that none of our tests are better than any other's. That is what prompted me to go looking for scientific FACTS. I have found many (pages upon pages) that support temperature changing combustion levels but I have yet to find any that support humidity's claimed effect or at least to the degree some say. This coincides with what my own limited testing produced.

Being that I've heard this "theory" from some reputable shooters, I thought it would be no problem for them to produce some evidence of it in a scientific matter. That means forming a hypothesis and proving it in scientific method. But as of yet, you and they have not. Saying that Ratigan says powder absorbs moisture is not going to cut it. He's a top shooter but does that make him a powder expert? Does that give him a PHd in chemistry? NO. It just means he can shoot well.

As I said before, I am simply putting this thread out there for someone to either prove or disprove the idea. I have been fairly neutral in accepting the possibilities. When I first started this short range game, I heard this humidity problem and gave it a shot to prove out. But neither the books, the ballistic programs, or the powder manufacturers can prove that it exists. Since I have learned in the following years that short range benchrest is a "hotbed" for misinformation, superstitions, and biases, you can hopefully see why I just simply can't accept an idea as "fact" just because MR. Shooter says so. Please forgive me if this sounds brash, but I feel that perpetuating myths without scientific proof is the last thing we need to be doing. The learning curve for what it takes to win a 2 gun is already steep enough without diluting it with further misinformation. Fair enough?
 
Ratigan does not say that powder absorbs moisture. Perhaps you missed the slight difference in spelling. He says that it aDsorbs moisture. Which is why I suggested that you may have asked the powder manufacturers the wrong question.
http://en.wikipedia.org/wiki/Adsorption
That was the point of my reference to a pile of sand. Now, does anything in your pile of scientific data speak to this issue? Perhaps it is time to redirect your inquiry.
 
I propose this:

ANyone; find a source, any source that's printed (be it internet searches, ballistic books, thesis papers, disertations, mathematical equations, lab test minutes, chemistry or physics notes) in a scientific "for the record" context that supports humidity affect on smokeless powder combustion. Then scan it, copy it, or re-type it here. Then this thread will be put to rest. It's a CHALLENGE!
 
Ratigan does not say that powder absorbs moisture. Perhaps you missed the slight difference in spelling. He says that it aDsorbs moisture. Which is why I suggested that you may have asked the powder manufacturers the wrong question.
http://en.wikipedia.org/wiki/Adsorption
That was the point of my reference to a pile of sand. Now, does anything in your pile of scientific data speak to this issue? Perhaps it is time to redirect your inquiry.

Ok. That would make sense and is plausible. My references don't mention it but it would be a different subject and inclusion would be coincidental.

So how do you or Ratigan propose that kernels of powder with moisture "adhered" to it would provide the results you've detailed? Do you claim that adsorption faulted powder would measure differently, burn differently, or otherwise need to be accounted for?
 
Now, go back and reread my account of Borden's experience, and rethink Jackie's, and Bob's. You completely discounted what we told you because of the narrow approach to the issue of how humidity might have an effect on powder. BTW we are here to share our experiences. Most of what we experience in life is anecdotal. This does not mean that these experiences are irrelevant. When someone tells of his experiences, his is giving you something that usually cost him time and very often money...for free. It might be a good idea to get in the habit of listening.
 
Now, go back and reread my account of Borden's experience, and rethink Jackie's, and Bob's. You completely discounted what we told you because of the narrow approach to the issue of how humidity might have an effect on powder. BTW we are here to share our experiences. Most of what we experience in life is anecdotal. This does not mean that these experiences are irrelevant. When someone tells of his experiences, his is giving you something that usually cost him time and very often money...for free. It might be a good idea to get in the habit of listening.

Well said Boyd :)

al
 
Now, go back and reread my account of Borden's experience, and rethink Jackie's, and Bob's. You completely discounted what we told you because of the narrow approach to the issue of how humidity might have an effect on powder. BTW we are here to share our experiences. Most of what we experience in life is anecdotal. This does not mean that these experiences are irrelevant. When someone tells of his experiences, his is giving you something that usually cost him time and very often money...for free. It might be a good idea to get in the habit of listening.

Whoa Boyd. I don't think you need to go there buddy. This thread has gone on for 4 pages now and you didn't bring up the Adsorption idea until just a few minutes ago so I don't think you need to act like I wasn't listening or ignoring what you guys said. It is a different term entirely than what we had been talking about for over a week! And I did go back and read what was said. Correct me if I'm wrong but neither Jackie, yourself, Bob K., or anybody else ever said anything about adsorption. I can quote your posts here if you don't believe me.
Furthermore, you could re-read my experiments (which are free to read but cost me time and are far from irrelevant too) and say the same thing about them you did of other tests. My results just varied from what you wanted to believe so you discounted them immediately.
And lastly, you still haven't answered my question from my last post. Now that you have introduced adsorption into the equation, you need to explain how you think it affects rifle tune and/or find data to support it.
See, there are people out there that have been following this thread that are thinking, "ok whether it's humidity, hygroscopy, or adsorption, I don't care what the terminology is. What I want to know is why does it do what it is that people say it's doing and how do we account for it".
Can you explain it? Believe me, I'm listening!
 
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