Variations in case weights Win vs S&B

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bb07

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I've used mostly Winchester brass ever since I started reloading about thirty years ago. The past few years I haven't been doing any reloading at all since I had enough loaded up to last me a lifetime, and then some. But now I'm back at it with a vengeance but some changes have become apparent.
Most notably, it seems that Winchester quality control has slipped. This thread is a good example: http://www.canadiangunnutz.com/forum/showthread.php?815553-Winchester-ammo-quality-or-not

I decided a little test was in order. I was curious how Winchester brass would fare (after the varying case lengths shown above & iffy quality)
The cases are all .308 Win caliber, all once fired with the primers still in.
The Winchester cases were originally factory loaded Super X 150gr Power Points.
The results of weighing 10 Winchester cases are:
The lightest weighed 156.7 and the heaviest weighed 162.3 -a difference of 5.6 grains. These were picked at random out of a couple hundred.

Next I did the same with Sellier & Bellot cases, which were originally factory loaded with 147gr FMJ
Weighing ten of these revealed quite a difference. The lightest weighed 179.8 and the heaviest was 180.8
One grain difference! These cases are not only heavier than the Winchesters, but are amazingly consistent for fairly inexpensive ammo.
Whether this makes any difference at all with regard to accuracy, I don't know, as I'm not a precision shooter by any means. I'm more of a shoot it & eat it kind of guy, with off season shooting being more
rolling a tin can around than trying to punch tiny clusters in paper.
So to you precision shooters: what do you think of the differences in case weights with regards to accuracy? Does it make that big of a difference?
I'd like to hear your thoughts, thanks.
 
Look here: http://www.canadiangunnutz.com/forum/showthread.php?413425-308-Win-Case-Volume-Differences

Powder capacity goes down as brass weight goes up, but there are a few anomalies.

Brand - Weight - Volume (of H2O)

Hornady Match - 159 grs - 58 grs
Dominion - 160 grs - 58 grs
Federal - 162 grs - 57 grs
Winchester - 168 grs - 56 grs
Hirtenberger - 168 grs - 58 grs
Norma - 170 grs - 57 grs
Remington - 170 grs - 56 grs
Lapua - 177 grs - 55 grs
IVI - 187 grs - 55 grs
DA - 196 grs - 53 grs
 
I weighed two boxes of Dominion .30-06 over 40 years ago when the idea was first floated.
Box 1: 186 - 203.
Box 2: 183 - 206.

The inconsistency was so great there was no need for decimals. Selected 20 out of the middle.
Weighing of brass is essential.

Norma 6mm brass, two boxes, 1.1 grains variation.
 
Thanks guys. I'm aware that powder capacity is normally reduced as brass weight goes up (thicker brass=less volume), and that different brands vary tremendously. The weights of the Winchester brass as I've shown varies by a lot. And I realize that for the ultimate in accuracy, someone like a benchrest shooter would weigh their cases to be more consistent, but what I'm wondering though is this: how much do different weights (within one brand) of brass affect accuracy? With a spread of about 5 1/2 grains like the Winchester that I weighed as above, would accuracy really suffer, or would the average person not even notice? Before someone tells me to go shoot and find out, I don't have the means right now (or a rifle with extreme accuracy) to go and do some testing to see for myself, so that's why I was asking.:)
 
Accuracy suffers if the components are not exactly the same. Therefore the benchrest shooters, will weigh and measure everything. Brass, initial sorting, get the 50 or 100 pieces you need, with the least amount of variation in weight, then sort from lightest to heaviest. Brass prep would be the same on all this brass, same head stamp and same lot. Enjoy.
 
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