8208brx fails a test..but only one..will you retest ?

We have some truely great measures being made, but I am not
naive enough to believe that any are made that can overcome
human error. That some great groups have been shot with loads
checked or weighed on lab scales is at this point IMO not proof
that it is a must do. Some can run measures much better than
others and some could not reliably make 12 ice cubes in a 12 cube
tray. It has been said by great shooters , that 8208 has a window
a truck could be driven thru. If the new stuff will only accomodate
a fair sized SUV, I'd be happy. That it lacks the odd and irregular
grains that plague 133 is a big plus. That VV was made from cotton
apparently was not as important as we believed. The 8208brx shows
great promise, nothing is perfect
 
Bob

I do not think there is a hill of beans difference in any of the current powder measures. They all work exactly the same way. Gravity. If you do exactly the same thing every time, they will all throw pretty consistant.

What we are all finding out is, it's the darned powder that makes the biggest contribution to how accurate, or inaccurate, a measure will repeat from one throw to the next.

Well, I will qualify that a little. We have all known it, but just ignored it under that old premis, "if it's in the load window, a few tenths one way or anoher makes no difference".

Contrary to what those that are ignorant of this game believe, Benchrest is not "stagnant". There are small, but very significant steps being made all the time that helps shrink the aggs just a little more.

This whole powder weighing thing is probably one of those..........jackie
 
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Jackie

I would not disagree, and in the coming season we will see more people
weighing on very good scales. Clearly we will all learn something. If weighing
allows you to define your tune and adjust for it quickly, its a win-win. But Few
registered matches offer the condition that were had in st louis , so it
will be a slow road. I doub't that many matches will be won this year
where .02 in charge difference is the deciding factor. With a hundred
flags before you and 7 minutes, it is quite a chess game.
 
your right, I need a .01 scale

mike in co said:
a tenth does not cut it. if your scale cannot resolve to .02/.03 or less...it just does not make it in this test.

3 out of 10 is a 30% error......

read the original request..."if and only if your scale " can resolve low enough to tell the diff. a +/- 0.1 does not work.

thanks for your input.
mike in co
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but for now all I can do is test the new powder against the powders Ive shot in the past with the equipment I have. This morning after paying closer attention to my powder throwing technique and letting my scale warm up I was able to throw 21 charges in a row at 29.5, never seen this with 133.:D
 
this is but one characteristic of a new powder. we have seen that old and new 8208 can shoot. for some(like me) we maybe able to compensate for our poor wind skills with a tad better load. for those at the top end, that can tune, that can read the wind, the use of weighed charges may just give them an advantage.....a small advantage that poor gun manners or an evil wind can take away quickly.
its a game..its why we play.


i aplaude the building of a new powder for our sport.
( a fleible powder that has other uses!)
powder valley is already out........

thanks
mike in co
 
I agree

Like Jackie said, small improvements are what keeps this sport from standing still. I have been weighing my charges on a analytical scale with .002 gr. resolution, and storing them in test tubes. I weigh around 75 charges of each weight. There is the load that's supposed to shoot, then there are the lighter and heavier charges. That makes for a lot of weighing, but I only have to replace the ones I use, so it get easier with time.

Question.
If you change your PPC load by .3 gr. up or down to find the tune, why would you believe you will not lose a shot out of the group with a charge that is .3 grains lighter or heavier than the rest?

I have chronographed my weighed charges using Wolf primers in the 30-30. I have seen 5 shot extreme spreads down around 3 fps. If I find a tune, and get in the middle of the window (with luck), I'm not likely to have a shot outside the window of tune. I have seen improvements in agging ability. Obviously I have a few tricks like this to make the 30-30 shoot competively against the PPC. If my efforts were a waste of time, I think it would be very evident in my case.

Michael
 
mturner said:
Like Jackie said, small improvements are what keeps this sport from standing still. I have been weighing my charges on a analytical scale with .002 gr. resolution, and storing them in test tubes. I weigh around 75 charges of each weight. There is the load that's supposed to shoot, then there are the lighter and heavier charges. That makes for a lot of weighing, but I only have to replace the ones I use, so it get easier with time.

Question.
If you change your PPC load by .3 gr. up or down to find the tune, why would you believe you will not lose a shot out of the group with a charge that is .3 grains lighter or heavier than the rest?

I have chronographed my weighed charges using Wolf primers in the 30-30. I have seen 5 shot extreme spreads down around 3 fps. If I find a tune, and get in the middle of the window (with luck), I'm not likely to have a shot outside the window of tune. I have seen improvements in agging ability. Obviously I have a few tricks like this to make the 30-30 shoot competively against the PPC. If my efforts were a waste of time, I think it would be very evident in my case.

Michael
Click to expand...


Well said Michael! :)

al
 
mturner said:
Like Jackie said, small improvements are what keeps this sport from standing still. I have been weighing my charges on a analytical scale with .002 gr. resolution, and storing them in test tubes. I weigh around 75 charges of each weight. There is the load that's supposed to shoot, then there are the lighter and heavier charges. That makes for a lot of weighing, but I only have to replace the ones I use, so it get easier with time.

Question.
If you change your PPC load by .3 gr. up or down to find the tune, why would you believe you will not lose a shot out of the group with a charge that is .3 grains lighter or heavier than the rest?

I have chronographed my weighed charges using Wolf primers in the 30-30. I have seen 5 shot extreme spreads down around 3 fps. If I find a tune, and get in the middle of the window (with luck), I'm not likely to have a shot outside the window of tune. I have seen improvements in agging ability. Obviously I have a few tricks like this to make the 30-30 shoot competively against the PPC. If my efforts were a waste of time, I think it would be very evident in my case.

Michael
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us michael's have to stick together!
mike in co
 
As long as we're kicking around opinions & not pretending they are proven . . .

I'd sort of agree with Michael. Remember, he also swages his flash holes to a consistent diameter, and I wouldn't be surprised to learn he does other things that insure the metering of the primer flash for consistent ignition.

All too often we get fixated on one thing (weighing powder charges, for example), without considering they are a part of a system, and improving one part of the system while ignoring the others gives very little gain.

The biggest problem with ensuring consistent powder burn might be that we are not sure we know all the variables.

The second biggest problem, when you get down into the milligram region, is (1) evaluating the scales, and (2) knowing what affects them. I've used analytical balances -- the old, mechanical ones -- to weigh to .1 milligrams or less. You'd be surprised. At some point, you get into a situation equivalent to machining to .0001 inches -- it takes a controlled environment as well as some practice.
 
Load window

The next test IMO is the load window. The original info on this powder says you shoot from 29.8-30.2 with no change in group size. I plan on testing with varying loads in each group from .1 to .6 gn up and down at each of the higher nodes.
 
yep i agree.
i hope peole as they get a chance to shoot it will post there results..in another thread, and list if they throw or weigh thier charges.

its what happens on the paper that counts....all else is this winter bs shooting.

lol
mike
 
Why the change in size?

Please excuse me if this has already been asked, but has anyone asked why the change in kernel size with the new production 8208? It seems odd to me that there was such a change after all the favorable reports on the original production unless it is a quality control problem that will pop up with each lot produced varying from the prior one(s).
 
Rick
You need to understand that the current 8208 is not produced by the same plant as the original. Or even the same country for that matter. So instead of reproducing the powder using a known formula, the current manufacturer went about trying to reproduce the known burning and ballistic characteristics. Maintaining kernel size was probably not within the scope of manufacturing possibility or practicality.
Ted
 
Rick B said:
Please excuse me if this has already been asked, but has anyone asked why the change in kernel size with the new production 8208? It seems odd to me that there was such a change after all the favorable reports on the original production unless it is a quality control problem that will pop up with each lot produced varying from the prior one(s).
Click to expand...

Not a great pic but. Dupont IMR 8208 on the right. ADI IMR 8208XBR on the left.
 

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hecksf said:
Rick
You need to understand that the current 8208 is not produced by the same plant as the original. Or even the same country for that matter. So instead of reproducing the powder using a known formula, the current manufacturer went about trying to reproduce the known burning and ballistic characteristics. Maintaining kernel size was probably not within the scope of manufacturing possibility or practicality.
Ted
Click to expand...

True enough, but the burning rate of most powders is a function of the deterrent coatings rather than the powder itself (most powders are supposedly the same basic formula). The surface area to volume ratio (of the kernel) reportedly has surprisingly little to do with the burn rate (within the burn rates of small arms cartridge powders). Conventional deterrent coatings are really just surface coatings and are consumed fairly early in the combustion process. The one exception I am aware of may be the different coating process used in Rel 17 which is supposed to penetrate much deeper into the powder.

Though none of the powder people I have spoken with have said so in as many words I have come to suspect that ease of manufacture has as much to do with it as anything else.

As I recall it, there was some degree of success experienced by the people who screened their powders with a series of sieves, which is not really surprising when dealing with thrown charges.

Cheers
 
Hunter chamberings

With all due respect....
In the days when the T was around it was used quite successfully in the Hunter cartridges. Has anyone tried it yet??? :eek:

David
 
david,
i got into br in the last 6-7 years, so did not know about the use in anything other than THE br round. now that i have seen data on others i plan on trying all 5 lots(4 early plus new) in my 308win br.

mike in co
 
jackie schmidt said:
I was at my shop a few hours ago, and I broke open a bottle of the originol 167-8208, and yes, the kernals are smaller, and more uniform, than the new XBR.

I agree as well, one of the successes of 8208 probably lies in the fact that meters much more consistantly than 133. In an inviroment where thrown charges is the norm, that would be a big advantage, that is, if you could arrive at a competitive tune...........jackie
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Ok
Just for discussion sake lets say that Jackie's last paragraph is valid.
Then Maybe just maybe we haven't really been tuning our rifles.
Maybe we have been happening upon a set of variables that have allowed us to throw charges more consistantly that in turn have allowed our guns to shoot more consistantly! Inturn a better agging capability.

As an example. Jackie has stated in the past that he would have trouble tuning N133 when the humidity changed. Maybe that change in humidity caused his powder measure to not throw N133 as well as was needed for a good tune ?


SO in other words maybe we have been tuning our powder measures!!!!!!!!!
Ted
 
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hecksf said:
Ok
Just for discussion sake lets say that Jackie's last paragraph is valid.
Then Maybe just maybe we haven't really been tuning our rifles.
Maybe we have been happening upon a set of variables that have allowed us to throw charges more consistantly that in turn have allowed our guns to shoot more consistantly! Inturn a better agging capability.

As an example. Jackie has stated in the past that he would have trouble tuning N133 when the humidity changed. Maybe that change in humidity caused his powder measure to not throw N133 as well as was needed for a good tune ?


SO in other words maybe we have been tuning our powder measures!!!!!!!!!
Ted
Click to expand...


lol nice ted...
not sure about the "why"
but i do agree with some powders...n133.....the powder measure is part of the problem/solution....

mike in co
 
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