40 Rod & Frog,
  Have either of you looked over the experiments that Ed Stutz and myself performed? Please do so. You will find my work on my web site at

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which will then direct you to Brent's site where Ed's work is published and Brent's analysis of the results is given.

  The reason the old timers kept track of temp. and humidity was not because BP attracts moisture, it was because temp. and humidity affect the bullets flight. The longer the range the more critical this is and at the Creedmoor matches the shooters even kept track of barometric pressure.

  During some testing Ed did one Summer here are some coclusions he came to regarding the effects of temp. and humidity on MV's using BP..

As humidity decreases velocity increases 2 fps per 1% change

  As humidity decreases wt of powder drops .1gr per 1% change

  Velocity increases 1.8 fps per 1 degree increase in temp.

  I hope this will clarify some of your thinking!

PETE

DonH,
  Good question, and not sure I can answer it to your satisfaction.

  Roughly.....The ingredients in BP are ground together into almost a dust like consistency, mixed with water and pressed into a "cake". When it is dried to a certain point it is broken up and put into polishing drums which harden the surface of the individual grains. Part of this process is the addition of graphite.

  What you have when you get done is almost the equivalent of a coupla coats of varnish on that wood door you mention. Like the door, if the powder has been properly treated it will resist the absortion of moisture.

  I assume you have looked at the tests run by myself and Ed Stutz. Those are FACTS!! If people wish to disbelieve them and except long standing myths then that's their perogative.

  Since there doesn't seem to be any interest I won't carry out an experiment I had in mind to further prove, or disprove, this point.

PETE

Pete;
Just an added thought. If that "door" is exposed to the elements ( or sometimes even in interior space) it takes a highly impervious "varnish" coating 360 degrees to prevent moisture absorption. Not an easy nor a casual thing.

BTW, I am always a hard sell when someone comes up with something new which no one ever thought of before.

DonH,
  Don't blame you for finding it hard to believe, but if you will look the evidence of the tests over it's hard not to believe. Plus there is nothing says you can repeat the experiments to see for yourself.

  If you will look at my message detailing what Ed found out were the changes in MV with changes in temp. & humidity you will see a discrepancy that was one of the reasons we did the test. I thought sure someone would pick up on that and try to use that as a counter to the experiments. Guess I'll have to bring it forward myself. The original idea for the test was a thread on BP-L about just this moisture absorbing myth and how many of the top shooters would open a new can of powder every day of a match. This didn't seem quite right to me and thus the experiment.

  Like all of you Ed thought that BP absorbed moisture and thought my experiment was flawed in some way so he figured he'd do a repeat in his part of the country to prove the results wrong. He didn't, as you can see from the results of his work.

  To answer you latest question tho, the reason the BP granules don't absorb moisutre is as I stated. Think about it. The grains are rolling arond in a polishing barrel with a great deal of other grains. I forget what a charge weghs but there is quite a bit of wgt. bearing on each grain. This wgt. tends to compact the surface very tightly. This tightness is one of the factors that differeniate sporting grade powder from musket and rifle powders. The longer you leave the powder in the polishing barrel the harder and thicker this surface becomes. Then when you add a slight coating of graphite this only adds to the imperviousness of the grains to moisture.

  An experiment I was thinking of running if some positive replies had been given was to take a given wgt. of powder and put it into an open top pan and leave it exposed to atmospheric conditions on a shelf in the garage for an extended period of time. I'd weigh it every day to see what the changes in wgt. were, and to see if at some time in the future it actually did pick up moisture/wgt. I'd report the results every few days or so, so you all could keep up with things. At the end of a month... six months... whatever was agreed upon..... the charge would be put in the oven at 150 degrees F. and allowed to dry out, and then weighed. Would have made and interesting experiment!

PETE

Brent,
  Wondered about that. But the house is air-conditioned and the temp. and humidity in the basement stay pretty constant. I have a dehumidifier down there for keeping the lathe and other tools from rusting. The garage was the only place I could think of offhand to put it.

  But since there doesn't seem to be any interest there's not much sense doing it. I don't plan on leaving a can open longer than a 24 hr. period anyway, nor do I think anyone else is either.  But thought it might be of interest to see just how long it does take for BP to deteriorate to the point where it might absorb moisture. Probably just one of those useless bits of minutae (inside joke) that would rattle around in your head.

PETE

Charlie,

 Ahhh! You've caught the "fly" in the ointment.

 Yes, the part of Ed's work says what you think. The problem is, is that it was written under the same assumption we all had prior to the testing we did. As you might notice in the message I addressed to DonH you will see where I address this, altho in a roundabout way. I wanted you, or someone else to "discover" it.

 When I did the test as outlined in the message to Brent there were some questions in my mind as to why some shooters would open a new can of powder each day of a match. I figured that BP couldn't be THAT hygroscopic! After I did the test and posted it on BP-L Ed didn't really believe it so thought he'd do it himself. Which he did and found out exactly what I had found out. Brent did the statistical analysis to see if there was enuf evidence to, however small, to show that possibly the BP sample did pick up some moisture. His conclusion was that statistically there was no evidence that it had.

 Now both experiments only covered a 24 hr. period, and satisfied the question about the sample absorbing moisure in that time frame. Another experiment I did following this, but which I dont have on the web site, was putting the sample in the oven, under Bill Knights directions for a period of time to dry it out. This was to see, again, if the sample had picked up moisture we couldn't detect. After drying the sample was weighed as fast as posibble after removal from the oven. No detectable change in wgt. was noted.

 You are right about fouling being a whole 'nother kettle of fish. But we didn't have a way of really getting a sample directly after firing, weighing it, and then repeating the experiment along the lines of unfired powder. This would probably be useless since everyone can easily provide anecdotes proving this.

 As for doing the experiment in your basement... be my guest. I for one would be very interested in what you find out over an extended period of time. Offhand I would assume that somewhere along the line moisture will penetrate the "skin" and the sample will pick up wgt.

 As you say... the more input we have the more we all learn.

 On the electronic scale.... Personally I wish you would use a standard beam balance. My experience with electronic scales shows most of them as being of limited use and not as sensitive as the other type.

 Powder..... I don't suppose it would make any difference other than I used Elephant. Forget now what Ed used. Just make sure you take your sample from a new unopened can so the experiment will be as unbiased as possible.

 If you decide to give it a try possibly we can get Josh to split off all the messages dealing with this and put it under a new thread. What do you think?

PETE

Well, you guys will just have to do your own experiments I guess.  I imagine a month or two in a mushroom cellar might lead to greater moisture absorption.  I have no idea what the utility of that information might be however.  If you spend a month in a mushroom cellar between shots, perhaps there is something to it.  But the issue that started this was the "need" to adjust measures in the middle of a match due to atmospheric variation in humidity causing changes in gunpowder.  And for that, the Pete-Ed-Brent experiment is pretty tough to argue against.  Not that you guys seem to lack for ambition in that department though.  So, have at it.  Me, I'm moving on to another myth.  I used to keep track of all the bp-fables I heard when I started this game and how many of them were absolutely gospel and now, how many of them have fallen?  There is a good article or three in there for someone to write I think. 

Brent