I will let you find that answer. ;D Personally I don't care we get our drinking water from the county. And the get it from the run off from the pastures. ;D My house goes from air to heat and the humidity in my reloading is the same temp and humidity is low . Larrybrians356 said:
Letting Powder Breathe ??
- Thread starter GNERGY
- Start date
I live 48' above sea level and the water table in my yard is 14'' right now. or not two post hold digger blades. Larrybrians356 said:
BoydAllen
Gold $$ Contributor
Getting back to the original question...while I am pretty sure that there is no safety issue, there may be one relating to tune. In the article, letting open cases sit around let the powder dry enough to increase velocity by almost 100 fps. Of course in a basement that was not as dry, that number would be smaller, perhaps negligible. Personally, I hope that he has some data so that he can note any velocity difference.
Varget us to be my powder of choice . Between lots I had as much as 50 ' difference . So I would mix the lot together . It would take some time and many of time of mixing. I had to do it outside because of the smell. I would bring it inside and leave it open to the humidity in my house. I have 3 8# that is mixed that way. The other two are un open but the same lot
H4350 I got 4 8#containers. all the same lot . I leave it on the hopper of my charge master. When I'm done reloading I fill the hopper and just put the lid on it. My ES stay very low doing it that way . Is it correct? It works well for me.
Larry
H4350 I got 4 8#containers. all the same lot . I leave it on the hopper of my charge master. When I'm done reloading I fill the hopper and just put the lid on it. My ES stay very low doing it that way . Is it correct? It works well for me.
Larry
BoydAllen
Gold $$ Contributor
It seems to me that ES and accuracy nodes are two somewhat separate issues that both need to be addressed for long range, while only one for short range. Having a good ES is always a good thing, but it is not the same thing as being in tune for the days conditions.
Going to an example that I am more familiar with, Gene Beggs, who has a 100 yard testing in which a lot of testing has been done, has said that the weight interval between accuracy nodes for 133 is about 1.2 grans for the typical 10.5 weight limit LV/Sporter rifle. If we assume that the range for best accuracy is less than half of that, we are at .3 to .4 grains width. Looking at the Berger manual data for 68 gr bullets propelled by 133 we can compute an average velocity change per grain of powder as 106 fps, so the .3 to .4 node width would equate to a range of from 32 to 42 fps. Comparing those numbers to the reported amount of moisture reduction and consequent increase in velocity cause by simply letting cases sit open in a dry basement, one might logically conclude that doing a little velocity testing each time that we load (more easily done when loading at the range) might be a good procedure to follow.
Some time back, short range shooter, gunsmith, and former IBS president Jim Borden told me about a time when he preloaded a total of (if memory serves) 300 rounds for the Nationals. Each week, while at the range he adjusted his load to produce the velocity that he wanted (which remained constant throughout his loading of all of the rounds) and loaded a single batch of 50 or 60 rounds ( I forget). During those several weeks the weather, and with it the humidity varied greatly, so much so that his records showed and extreme spread (comparing batches) of powder weights of 1 1/2 grains. Just before the match his traveling partner said that he thought that Jim had made a mistake with his approach so Jim pulled rounds from all the lots and combined them to fire some five shot test groups, which confirmed that his method was correct. The groups were good. I suppose that I should mention that he believes tune to be, in his words, "velocity specific". Perhaps all of this might be worth considering for those whose type of competition may dictated preloading.
Going to an example that I am more familiar with, Gene Beggs, who has a 100 yard testing in which a lot of testing has been done, has said that the weight interval between accuracy nodes for 133 is about 1.2 grans for the typical 10.5 weight limit LV/Sporter rifle. If we assume that the range for best accuracy is less than half of that, we are at .3 to .4 grains width. Looking at the Berger manual data for 68 gr bullets propelled by 133 we can compute an average velocity change per grain of powder as 106 fps, so the .3 to .4 node width would equate to a range of from 32 to 42 fps. Comparing those numbers to the reported amount of moisture reduction and consequent increase in velocity cause by simply letting cases sit open in a dry basement, one might logically conclude that doing a little velocity testing each time that we load (more easily done when loading at the range) might be a good procedure to follow.
Some time back, short range shooter, gunsmith, and former IBS president Jim Borden told me about a time when he preloaded a total of (if memory serves) 300 rounds for the Nationals. Each week, while at the range he adjusted his load to produce the velocity that he wanted (which remained constant throughout his loading of all of the rounds) and loaded a single batch of 50 or 60 rounds ( I forget). During those several weeks the weather, and with it the humidity varied greatly, so much so that his records showed and extreme spread (comparing batches) of powder weights of 1 1/2 grains. Just before the match his traveling partner said that he thought that Jim had made a mistake with his approach so Jim pulled rounds from all the lots and combined them to fire some five shot test groups, which confirmed that his method was correct. The groups were good. I suppose that I should mention that he believes tune to be, in his words, "velocity specific". Perhaps all of this might be worth considering for those whose type of competition may dictated preloading.
Low ES and accuracy has always be two separate issues.
But you must have both for great accuracy. No matter what you shoot or how far. When someone tells me about history it means nothing any more.
Look how many records have be broken in the last two years.
Larry
But you must have both for great accuracy. No matter what you shoot or how far. When someone tells me about history it means nothing any more.
Look how many records have be broken in the last two years.
Larry
BoydAllen
Gold $$ Contributor
Larry,
To my knowledge no one in short range benchrest anneals, measures powder to the granule, or worries much about ES. They load between matches, generally throwing charges or using Chargemasters. This is not history, it is current practice. If you look in the current record book you will see my friend Gary Ocock's name. all of those records were shot with thrown charges, and some of them are quite recent. In the case of the newest powders LT 30 and Lt 32 they can be thrown as consistently as they can be measured with a Chargemaster, perhaps even a bit better. The information that I gave about tuning nodes is not time related, and the information that I relayed from Jim Borden was to illustrate a point that is timeless as well. The same is true of how powder is affected by moisture, something that, judging by the responses in this thread, not many are aware of, which was the precise reason for my bringing it up. This is not old stuff, it is stuff that is so little known that it will be brand new to most who read it.
Boyd
To my knowledge no one in short range benchrest anneals, measures powder to the granule, or worries much about ES. They load between matches, generally throwing charges or using Chargemasters. This is not history, it is current practice. If you look in the current record book you will see my friend Gary Ocock's name. all of those records were shot with thrown charges, and some of them are quite recent. In the case of the newest powders LT 30 and Lt 32 they can be thrown as consistently as they can be measured with a Chargemaster, perhaps even a bit better. The information that I gave about tuning nodes is not time related, and the information that I relayed from Jim Borden was to illustrate a point that is timeless as well. The same is true of how powder is affected by moisture, something that, judging by the responses in this thread, not many are aware of, which was the precise reason for my bringing it up. This is not old stuff, it is stuff that is so little known that it will be brand new to most who read it.
Boyd
Dusty Stevens
Shiner
Bart just set 2 new records last week one was a sub teen agg with thrown charges chasing the tune all day. No chronograph was ever involved in any short range record and id bet maybe one or 2 have ever even shot their ppc over a chronograph ever. Id hate to know i was going to the line with a load with a low ES that didnt shoot. The target tells way more than a chronograph ever can but you gotta know how to read it and know what the wind did to you.
That's what I like about bench rest shooters. The last time I shot bench rest I had Billy shoot my gun. He told me it was a winner. He ask what I was shooting I told him what I had done .
Bart told me Mirage was my friend.
After two days I proved them both wrong. ;D ;D ;D ;D
I did get the second small .
Yes I did use a chronograph . The cases were annealed. The internal capacity was the same and I had low ES. ;D Larry
Bart told me Mirage was my friend.
After two days I proved them both wrong. ;D ;D ;D ;D
I did get the second small .
Yes I did use a chronograph . The cases were annealed. The internal capacity was the same and I had low ES. ;D Larry
Alex Wheeler
Site $$ Sponsor
I know that 2 IBS 1000 yards records were broken last year at our club without annealing or using a chrono.
OK,
Had a chance to get to the range today and shot the powder thru the chronograph
6.5X47 Lapua with 140 gr Hybrids and CCI 450 primers 2.700 OAL.
34.7 grs Varget, new powder 2791 fps average for 5 shots
34.7 grs Varget, powder that sat in cases since end of march 2778 fps average for 5 shots, That is 13 fps slower for powder that sat out. Group was about 1/2 inch larger also at 300 meters.
Tarey
Had a chance to get to the range today and shot the powder thru the chronograph
6.5X47 Lapua with 140 gr Hybrids and CCI 450 primers 2.700 OAL.
34.7 grs Varget, new powder 2791 fps average for 5 shots
34.7 grs Varget, powder that sat in cases since end of march 2778 fps average for 5 shots, That is 13 fps slower for powder that sat out. Group was about 1/2 inch larger also at 300 meters.
Tarey
brians356 said:
Whether the difference is significant depends on the standard deviation and the number of shots. For a single digit standard deviation, five, shots, and 13 fps difference in the mean, the difference would be significant.
brians356 said:
"Prove" is too strong a word. But there are standard statistical methods for determining whether two means are significantly different from each other at a given confidence level. If the means, standard deviations, and sample sizes are reported, then whether the means are significantly different (and the confidence level) can be determined.
It is a good point that a sample size of 5 is on the small size. A sample size of 20 would give a higher level of confidence, assuming the same means and standard deviations.
Back in the 60's, the muscle car crowd would meet on Fri & Sat night at the local drive-in restrauant. Inevitably, someone would want to challenge that their car was faster than another. The mantra was "Let'm breathe"...is this the same with powder 
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