  | For Those That Weigh Brass |
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08-21-2010, 12:12 PM
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For Those That Weigh Brass
Am doing some prep on 8mm Mag brass that I am fire-forming tomorrow with Bullseye (300 Jarrett) and when deburring the Inside of the flash hole where the punch pushes the brass during the manufacturing operation I have gotten as little as nothing to almost 2 grains worth.
Have not turned necks to clean them up as that will be after fire-forming as well as primer pocket clean up but------personally and the folks who trained me (the best known is Speedy) have always said weighing brass is a waste of time because you do not know where the difference in weight is coming from.
So if you do weigh it would make sense to completely prepare your brass before you weigh to sort for culls. Just something to think about...
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08-21-2010, 01:31 PM
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Re: For Those That Weigh Brass
Quote:
Originally Posted by Boss Hoss
Am doing some prep on 8mm Mag brass that I am fire-forming tomorrow with Bullseye (300 Jarrett) and when deburring the Inside of the flash hole where the punch pushes the brass during the manufacturing operation I have gotten as little as nothing to almost 2 grains worth.
Have not turned necks to clean them up as that will be after fire-forming as well as primer pocket clean up but------personally and the folks who trained me (the best known is Speedy) have always said weighing brass is a waste of time because you do not know where the difference in weight is coming from.
So if you do weigh it would make sense to completely prepare your brass before you weigh to sort for culls. Just something to think about...
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I weigh the cases after sizing, trimming, deburring and cleaning. I weigh them in groups and try to keep with the same weight in loading combinations. This gives me good results and Standard Diviations of less than 3fps and good groupings. Weight of cases has most of the time to do with the inside volume of cases. The more even the inside camber of the case the better for reloading.
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08-21-2010, 08:50 PM
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Re: For Those That Weigh Brass
Quote:
Originally Posted by Boss Hoss
when deburring the Inside of the flash hole where the punch pushes the brass during the manufacturing operation I have gotten as little as nothing to almost 2 grains worth.
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Boss Hoss,
Does this mean that when deburring the flash hole, from the case mouth side, that you are getting as much as 2 grains or so of "filings"?
I suppose you are using a deburring device that results in a constant flash hole depth from case to case?
Or maybe you could describe your flash hole deburring process.
Thanks
Roy
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08-22-2010, 09:13 AM
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Re: For Those That Weigh Brass
Quote:
Originally Posted by Boss Hoss
personally and the folks who trained me (the best known is Speedy) have always said weighing brass is a waste of time because you do not know where the difference in weight is coming from
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This is a fact, so why would you do it?
After fully prepped(including neck turning) & fully fireformed & straight from a smoking chamber, measure H20 capacity of each case to the mouths. With this, you'll know not only which cases depart from the others, but also the actual capacity of your matched cases -to validate future lots.
If for some reason you don't believe what I'm telling you, well you have a perfect opportunity to prove it to yourself right here.
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08-22-2010, 10:20 AM
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Re: For Those That Weigh Brass
This has been a long time controversy and will remain so because of this I did a test with
new unsorted brass and new fully prepared (Turned,trimmed, flash hole deberd, and full length
sized and weighed) The idea was to make the outside of the case as close to the size same
as possible so that any weight difference would indicate volume.
I realize that the extractor grove can vary in dimension but it was the easiest way to get them
as uniform as possible for the test.
I shot 5 shots through a chronograph and cleaned and dry patched after each cleaning.
The first 5 were as they came in the bag with all of the same components loaded as carefully
as I could to be consistant with each other.
The second 5 shot were the fully prepped and weighed followed buy the cleaning and dry patched
The third 5 shot string was the same as the first and the fourth and final 5 shot batch was the
fully prepped and weighed.
There were some interesting results and this is the reason I will allways prep an weigh all
of my brass before shooting Except on short range weapons (Under 50 yards).
The unsorted brass had a wide range of SDs ans ESs (from 15 to 30 SDs) the prepared and
weighed loads were 9 to 14 sd and were very consistant shot to shot with some velocities
duplicating other shot velocities.
The UN weighed case velocities were never the same and did not repeat a single velocity
of the 10 fired.
I do realize that weighing is not the most precise method to measure volume but it is an
easy way to get them close without a lot of hassle. ( I did try and measure volume with
the water method) and found it to be time consuming and with no apparant gain in
performance. So I ruled it out as a viable method for sorting brass.
I realize that some will disagree but that's what makes the world go round . And It works
for me so I will continue to weigh cases because it produces better performance and
consistency .All though it is not a lot of difference it is enough to make it worth my time.
This is just my opinion based on what I have found.
J E CUSTOM
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08-22-2010, 11:16 AM
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Re: For Those That Weigh Brass
So J E, your contention is that there is enough gain in doing 'easier' lesser things, to discount the 'tougher' better things..
Maybe. There are lots, of certain cartridges,, that correlate fairly well w/regard to weight-vs-capacity. I have seen this, and as well I've seen the correlation go to hell with different lots of the same cartridge and brass brand.
I have also found that no brand is better than another in holding consistent capacities.
There is no question from my experience that proper capacity checks are more accurate than brass weight assumptions. And you will never know without doing capacity checks anyway. Right?
Afterall, improved SD after weight batching may imply improvement, but not from matching case capacities, as they haven't actually been matched. This is just assumed so.
At any rate, it's rarely good habit to compromise merely for convenience.
With this, if you'll do it here, you'll do it there...
Lot of it going on around here, and ironically, the competitors among us seem worse about it.
Well, let's call it 'time management'..
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08-22-2010, 03:31 PM
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Re: For Those That Weigh Brass
Quote:
Originally Posted by Mikecr
This is a fact, so why would you do it?
After fully prepped(including neck turning) & fully fireformed & straight from a smoking chamber, measure H20 capacity of each case to the mouths. With this, you'll know not only which cases depart from the others, but also the actual capacity of your matched cases -to validate future lots.
If for some reason you don't believe what I'm telling you, well you have a perfect opportunity to prove it to yourself right here.
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Agree! I have used graded heavy sand (0% humidiity) for this in the past as water is problematic.
Temp and surface tension of water are difficult to deal with.
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