Segregate brass by weight or lenght?

[PaperSniper999]

An interesting thought I had the other day while day dreaming......I generally sort my new Lapua 6mmBR brass by weight, but I use a 50/50 scheme - I get the heaviest and lightest cases, then divide the difference by 2 and add that to the lightest case weight; cases under that are 'light', and heavier than that are 'heavy' for that batch of brass. To be honest I have not seen much difference in accuracy or consistency of the light/heavy cases.

I recently got a new 223 and decided to sort the new Remington cases by length....about half the cases were 1.753 or less the remainder where 1.753 to about 1.757. Not a huge difference in length, but I decided to segregate the cases by weight to see what happens. So far I have only loaded rounds using the shorter cases, and have not shoot any of them.

Just wondering if anyone has ever used case length for segregating cases and load development. Seems the difference in case length theoretically affects bullet tension, but whether the case length contributed significantly to bullet tension I have no idea.

Any experts out there to answer this one?

 

[memilanuk]

Rather than sort by length, why don't you just trim them all to a consistent minimum trim-length,1.750') and be done with it?

 

[PaperSniper999]

'Rather than sort by length, why don't you just trim them all to a consistent minimum trim-length,1.750') and be done with it?'

I plan to trim after the cases are fired from my chamber for the first time. I figured I'd check lengths again after all the cases have been fired, and probably trim at that point. I HATE to trim cases! <g>

 

[Winchester69]

There are two meaningful parameters for sorting brass.

The first is by volume. Most humans are averse to the practice. However, case volume does affect pressure.

The second is more practical for BR shooters. Cull, rather than sort, cases by variance in neck thickness, i.e., if a case exhibits variance beyond some chosen point, remove it from the group. Lesser offenders may be neck turned to achieve uniformity.

Sorting by weight assumes that some influential parameter, like volume, is varied by whatever caused the deviation in weight. Typically, there is no such correlation. Sorting by length is pretty much meaningless unless the case is an obvious defect.

 

[PaperSniper999]

I know you are spot on with the case volumes. I have never done that myself,using water to determine case capacity, etc), but I'm sure it's affect on velocity and thence consistency is more significant than the minor case length difference I will experience with my loads. But as you mentioned, I am one of those too lazy to do that! I take the easy way and use weight for my BR rifles!

'..Sorting by length is pretty much meaningless unless the case is an obvious defect. ....'

You are probably correct, at least in my case of loading for a Cooper 223 Remington. Since neither the rifle nor its caliber are known for 'benchrest' accuracy I doubt I see any difference in the loads using the short/long cases. Still, I think it's something about which it think, as I believe the case length affects the neck tension. I first thought of this,tension) when seating short little 40 gr bullets in the 223 cases. There is not all that much bullet being held by the case, especially with 'boat tail' bullets, so perhaps a .005 difference in case lengths might make an almost-significant difference in the bullet 'pull' upon firing.

Who knows.....and I have to wait a couple months to fire the loads I made for the Cooper; heading down to Florida this weekend for the annual fall pilgrimage. <g>

 

[Johnboy]

hey,just buy you a lee case trimmer and do the thing you dislike the most.it works really well and can be done with a cordless drill.sooner or latter you will have to do this,its a step that I go through every time I load up.rather be safe than sorry when reloading.

we are only here for the time that our maker gave us.so let's be safe at our love of shooting.

 

[hopefullbencher]

Hello,

I sort by weight but with a twist. First I have never bought new brass, I first full length size all of them then trim to length and then weigh them. Then look at the spread. The heaviest and lightest are compared and then the heaviest is checked for volume with water.

I have never claimed to be the sharpest knife in the drawer and am probably better off just doing what was stated above with just volume.