Pleasant Surprise

Jackie

I'm asking more about the bumpup in loads. EG. if you bumped your 31.8 XBR load to 32.4 to get your "tune back" would you have had to bump your 133 a similar (for 133) amount,or do you think 133 would be harder to tune @the lower temp.
 
I have NEVER loaded/tested a powder that would not drop in velocity with cold weather...and increase velocity in hot weather...NONE...NEVER...:mad:
How much they vary across the temperature range has never been tested to see if one varies less than all the others, but I gave up long ago believing that any powder can produce the same velocity by weight in 30 degree temps...that it will in 95 degree weather...it's like expecting your 8lb deer rifle to win the Sporter/LV grand at the Nationals...You should know better...:cool:
 
eww1350 said:
I have NEVER loaded/tested a powder that would not drop in velocity with cold weather...and increase velocity in hot weather...NONE...NEVER...:mad:
How much they vary across the temperature range has never been tested to see if one varies less than all the others, but I gave up long ago believing that any powder can produce the same velocity by weight in 30 degree temps...that it will in 95 degree weather...it's like expecting your 8lb deer rifle to win the Sporter/LV grand at the Nationals...You should know better...:cool:
Click to expand...


Bingo!
 
Jackie

Too bad this thread took a dump. I thought that there might be something (knowledge) to be gleened from your cold weather tests. I see others have different ideas :mad:.........Jackie if you would please PM me with more details of your tests........Thanks Roger T
 
Roger T said:
Too bad this thread took a dump. I thought that there might be something (knowledge) to be gleened from your cold weather tests. I see others have different ideas :mad:.........Jackie if you would please PM me with more details of your tests........Thanks Roger T
Click to expand...

I would also be very interested in your tests. This thread started out very interesting
 
No Big Deal

This is what we have found.

I did a test when I was sent a pound of the XBR. THe conditions that day were a really overcast and reary 53 to 55 degrees, a typical Houston Winter Day. The velocities with the top load of 31.8 grns was an average 3470-3480.
Accuracy was outstanding.

Last Saturday, the temperature was just about the same, but the sun was shining, the humidity was at 30 percent or less, a typical beautiful Houston day after a front comes through. The Rail,Gun was now locked into a bullet holes worth of verticle, and got worse as we dropped the charge. Only when we went up to 32.4 did the thing assume it's good manners.

We set my Ohlear 35P up and found that it now took 34.4 grns of powder to do what 31.8 did before. The only difference is instead of overcast and humid, it was clear and crisp.

Look, all we can do is put the rail gun on the bench, set the Chrono up, watch the flags, and try to shoot some good groups. I am certainly no "ballistitian". We just try to give real world results.

What we have found so far is we can get good velocity, great accuracy, a clean burn, and reasonble case life when the temperature is in the 50's. Although it takes more by weight to shoot the same as 133, it is more dense to the extent that it is no problem getting the upper load window charge in the case. We had to tweek it some when the weather, (not temperature), changed. Notice, I am trying like heck to avoid even uttering the word "humidity", because that would start a war of words that we best avoid.

I do suspect that when the weather turns warmer, the upper end load will probably be in the 31.5 grn. As to whether XBR will be overall easier to tune than 133, or anything else, I don't know.

But, in time, we will all find out.........jackie
 
So with both days you went out were the loads out of the same bottle of powder? (Same Lot)
 
jackie schmidt said:
This is what we have found.

I did a test when I was sent a pound of the XBR. THe conditions that day were a really overcast and reary 53 to 55 degrees, a typical Houston Winter Day. The velocities with the top load of 31.8 grns was an average 3470-3480.
Accuracy was outstanding.

Last Saturday, the temperature was just about the same, but the sun was shining, the humidity was at 30 percent or less, a typical beautiful Houston day after a front comes through. The Rail,Gun was now locked into a bullet holes worth of verticle, and got worse as we dropped the charge. Only when we went up to 32.4 did the thing assume it's good manners.

We set my Ohlear 35P up and found that it now took 34.4 grns of powder to do what 31.8 did before. The only difference is instead of overcast and humid, it was clear and crisp.

Look, all we can do is put the rail gun on the bench, set the Chrono up, watch the flags, and try to shoot some good groups. I am certainly no "ballistitian". We just try to give real world results.

What we have found so far is we can get good velocity, great accuracy, a clean burn, and reasonble case life when the temperature is in the 50's. Although it takes more by weight to shoot the same as 133, it is more dense to the extent that it is no problem getting the upper load window charge in the case. We had to tweek it some when the weather, (not temperature), changed. Notice, I am trying like heck to avoid even uttering the word "humidity", because that would start a war of words that we best avoid.

I do suspect that when the weather turns warmer, the upper end load will probably be in the 31.5 grn. As to whether XBR will be overall easier to tune than 133, or anything else, I don't know.

But, in time, we will all find out.........jackie
Click to expand...




Them chronographs come in handy once in awhile don't they Jackie? Aren't you glad you didn't sell it on ebay!? Last time I checked, an Oehler 35 went for almost triple what they originally cost but I wouldn't sell mine for double that!
 
goodgrouper said:
Them chronographs come in handy once in awhile don't they Jackie? Aren't you glad you didn't sell it on ebay!? Last time I checked, an Oehler 35 went for almost triple what they originally cost but I wouldn't sell mine for double that!
Click to expand...

Just think of the information you would get with a model 43;)
 
Dave Coots said:
Don't feel bad--90% of the thread was magically not worth reading.

Later
Dave
Click to expand...

I agree with you Dave but there must have been a lot of people who disagreed with us since the thread went over 4,000 views and five pages in just a few days! Somebody liked it even if they aren't saying.......
 
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It's like the demolition derby

the lurkers like to see the posters duke it out, not unlike the folks who like to watch car wrecks. It would be interesting to know how many lurkers there are.

Many posters become weary of discourse but the lurkers love it :)
 
Grouper

goodgrouper said:
I agree with you Dave but there must have been a lot of people who disagreed with us since the thread went over 4,000 views and five pages in just a few days! Somebody liked it even if they aren't saying.......
Click to expand...

May be the other 10% were really interested or very bored)chill(

Later
Dave
 
i just did half of a jackie....ordered 48 lbs of 8208(everyone knows texans do it bigger, did not want to get close...lol)
mike in co
 
jackie,
i know you posted it somewhere, but did not see it.
what are the lot numbers of your one pounder and your 8 lber's ?
just the last 4 digits should be enough.

both of my shipments are 4773 as in xxxxxxx4773

anyone else feel free to post thier lots
thanks
mike in co
 
Lot numbers

I have 1 pounders of lot 4736, and 8 pounders of lot 4798. I've seen mention of 8 pounders of lot 4773 mentioned here. Are there any others? Have any of you shot multiple lots, and if so, is the powder consistent from lot to lot?

Thanks,
-Dave-
 
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