Weigh sorting 6.5 creedmoor brass?

[hlee]

I've previously worked up a load with an SD of 7 (2700fps with 147 gr ELD-M) for this rifle using unsorted brass, but now that I have a bunch of empty brass staring at me I pulled out my scale and weighed all of them.

I'm sure this has been asked 100s of times, but what is your criteria for sorting brass? How fine are you sorting? 0.1 grain? 1/2 grain? 1 grain? I weighted 300+ pieces of mixed lot Hordady brass. These are all "at least" once fired brass, the vast majority fired through my rifle, but most were picked up at match stages, so some may be from other rifles. I know that a few are not mine as they are "Prime." (If you are looking for your 2 missing pieces of Prime brass, I have them...)

Ok, to the actual data...

All were weighed on my Gempro250, rounded to the nearest 0.1 grain.

Minimum weight 147 grains
Maximum weight 154 grains (excluding the 2 Prime cases that weighted 156 or more)
Average weight 150.4
St Dev 1.3 grains

91 pieces are within 1 grain of each other. 149.7 to 150.6
132 pieces are within 1.5 grains of each other. 149.9 to 151.3
171 pieces are within 2 grain of each other. 149.9 to 151.8
204 pieces are within 2.5 grains of each other. 149.4 to 151.8
235 pieces are within 3 grains of each other. 148.9 to 151.8

I would expect these numbers to be somewhat closer together if I were sorting out of a fresh bag of unfired brass, but what % would you expect to cull from factory loaded brass? How much does it matter for field shooting? I'm not a bench rest shooter- I'm shooting PRS style competitions.

I think I'm going to take the cases weighted at 148.9, 150.6, and 152.4 and load 6 of each at the load I have previously developed, then shoot them over my magneto-speed. That' the lightest and the heaviest weight for which I have 6 cases, and the midpoint of those 2.

In the interim, I'm interested to hear what you are doing- if anything- for sorting brass. Thanks.

 

[Steel head]

You have a 7 SD and you’re going to even bother to sort brass??????

 

[Rocketvapor]

The one heavy and maybe the two light ones were misformed. They are different.
The operator took a smoke break.
Everyone needs a couple pieces of brass to make dummies or modified cases.
What's 3 pieces of brass culled for experiments?

 

[Olen_4504]

god what a waste of time

go shoot lol

 

[Rocketvapor]

Based on about 250 shots, if your 7SD included the 'outliers' then sure, that was a waste of time.
I didn't count.

 

[JLP.Payette]

I get single digit SD/ ES and have never weighed a piece of brass.. Seems like a waste of time to me.

 

[yakstone]

Unless you have plenty of time on your hands and nothing else to do to keep your OCD in check.

 

[hlee]

Well, that's what I was looking for. Some people swear by sorting everything, and I was able to do the weighting this morning while on a conference call. Being that they are all weighed, I think I will still load up 6 from the top, middle, and bottom and see if there is anything interesting there. Beyond that, I'll just cull out the top and bottom few and march on. As someone else said (paraphrase) if the gun shoots, shoot it. Thanks!

 

[Olen_4504]

i think the biggest thing is... where is the weight difference between each piece?

the case head? the walls? hard to know. you could be culling out a piece of brass that weighs more but in an area that has no effect.