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heath
07-01-2010, 12:27 AM
I just received 200 Lapua 22-250 brass. They are same lot number. I sorted them by weight and figured I would share my findings. I am curious as to what degree of difference there is in accuracy compared to brass weight.

Weight Qty
160.1 gr 1
160.2 gr 7
160.3 gr 10
160.4 gr 26
160.5 gr 22
160.6 gr 29
160.7 gr 16
160.8 gr 24
160.9 gr 20
161.0 gr 19
161.1 gr 7
161.2 gr 6
161.3 gr 6
161.4 gr 6
161.5 gr 1

total deviation total weighed
1.4gr 200 brass

davejones
07-01-2010, 04:56 AM
"I am curious as to what degree of difference there is in accuracy compared to brass weight."

My guess would be not much, if any. Let us know how it actually pans out.

Joe Entrekin
07-01-2010, 09:54 AM
From what I have read over the years, brass within 1.5% weight variation is considered very good, and you are well within that standard. Now, with that said, benchresters can be pretty anal about such things. For instance, I have a 600 round batch of 30BR brass that only varies by .5 grain. It was plucked from a 1500 round batch of new brass. Does it show up on paper? Probably not, but one more variable that is eliminated.

Bill Wynne
07-01-2010, 11:25 AM
From what I have read over the years, brass within 1.5% weight variation is considered very good, and you are well within that standard. Now, with that said, benchresters can be pretty anal about such things. For instance, I have a 600 round batch of 30BR brass that only varies by .5 grain. It was plucked from a 1500 round batch of new brass. Does it show up on paper? Probably not, but one more variable that is eliminated.

Joe, I prefer to think of myself as picky about my brass. I do wonder if there would be much difference in groups with your rifle between the brass that you picked and the brass that you picked over?

Concho Bill

Joe Entrekin
07-01-2010, 11:58 PM
Bill, I ended up using essentially all the brass, but the other bunches were smaller. I doubt that a difference of 1 to 2 grains would show up much on targets. However, if having your brass weighed & sorted into minimally differing groups helps your confidence when competing, it can't help but improve your scores. Competing successfully is largely a "head" game afterall.

mks
07-02-2010, 12:28 AM
Here are weights for (396) 220 Russian cases after turning and trimming. Obviously one "oops!" case, but the others are pretty close, similar to yours. I separated into weight groups of a few tenths of a grain. Sorry, I don't have any accuracy results yet, but it feels good to know that at least the case weight variable has been addressed.

Cheers,
Keith


Number Weight, gns
1 107.2
2 109.1
7 109.2
3 109.3
8 109.4
5 109.5
13 109.6
19 109.7
24 109.8
32 109.9
45 110
47 110.1
54 110.2
57 110.3
38 110.4
12 110.5
14 110.6
5 110.7
5 110.8
2 110.9
2 111
1 111.1