Weigh Sorting Brass

BCBRAD

BCBRAD

CGN Regular
Rating - 100%
12   0   0
Location
Prince George BC
This morning I took 50 Lapua brass, 260 Rem, and weigh sorted.

Low weight was 171.18 gn, high 173.16 gn, average for the 50 was 172.09 gn.

I've decided on going 1/2 grain either side of the average.

Rounded off this is keep anything between 171.6 and 172.6 . This amounts to 27 kept out of 50.

Is this too narrow of a range? What have others found to be adequate?
 
Consider.... keep each weight group separated... fire them in your rifle with whatever load to form. It is very important to do this test with fireformed cases.

Now compare the CASE VOLUME of all cases... Does the WEIGHT of the case affect the case volume?

I use an ultra fine powder ... similar to salt... to compare case volumes quickly. Take any case that is fired (leave spent primer in the case), same trim length... pour in powder with funnel, overfill, tap case really well to settle powder as much as possible. Scrap powder to be level with the case mouth. Pour into another case. The powder volume should "overfill" but with tapping settle.

Is the powder charge at the same level? higher or lower?

Pour into another case and so forth.

Did any case weight contain more or less powder? and if so by how much?

Or were they all pretty much the same?

Jerry
 
I weigh match quality brass, but usually have 500 or 1000 pieces. I have little pails marked in 0.3 gr increments, and fill the pails. The pails at each end of the line only have a few pieces, and I use those for set ups, fouling shots, etc.

If I had those 50 cases, I would segregate them into 2 buckets. The light ones and the heavy ones.

Or, if I was real fussy, I would sort them into 2 boxes of 20 each, with the 10 ones too light/heavy as foulers.
 
Thanks to the above posters.

I think my weights are accurate for both case and powder, use a FX 120i.......makes short work of this.

The loaded 27 will be run in front of the Labradar to see what the velocities and groups (5 shot) look like at 300m.

I may sort out any out lyres in velocity and run again, figure my powder charges are accurate , one to the next.

Just wondering where the threshold of diminishing returns is at.

The 50 pieces are a starting sample, depending on results I'll do the rest.
 
At AccurateShooter.com there have been many posts about case weight "NOT" corresponding to case volume in the reloading forum.

The consensus with quality Lapua brass is load and shoot. And case volume is always checked with a fired case from "your" chamber.

Lapua .260 Rem Brass Proves Very Uniform
http://bulletin.accurateshooter.com/2013/03/lapua-260-rem-brass-proves-very-uniform/

Sorting cases by weight ??
http://forum.accurateshooter.com/threads/sorting-cases-by-weight.3898477/

Effect of Case Capacity on Velocity ES/SD
http://forum.accurateshooter.com/threads/effect-of-case-capacity-on-velocity-es-sd.3902292/
 
Last edited:
BCBRAD said:
Thanks to the above posters.

I think my weights are accurate for both case and powder, use a FX 120i.......makes short work of this.

The loaded 27 will be run in front of the Labradar to see what the velocities and groups (5 shot) look like at 300m.

I may sort out any out lyres in velocity and run again, figure my powder charges are accurate , one to the next.

Just wondering where the threshold of diminishing returns is at.

The 50 pieces are a starting sample, depending on results I'll do the rest.
Click to expand...

When you opened that box... :)

Do the volume check.... if you want to confirm volume consistency, measure the case volumes directly.

By all means compare groups with labradar data.... will be interesting to see what you find.

Jerry
 
Mystic Precision said:
Consider.... keep each weight group separated... fire them in your rifle with whatever load to form. It is very important to do this test with fireformed cases.

Now compare the CASE VOLUME of all cases... Does the WEIGHT of the case affect the case volume?

I use an ultra fine powder ... similar to salt... to compare case volumes quickly. Take any case that is fired (leave spent primer in the case), same trim length... pour in powder with funnel, overfill, tap case really well to settle powder as much as possible. Scrap powder to be level with the case mouth. Pour into another case. The powder volume should "overfill" but with tapping settle.

Is the powder charge at the same level? higher or lower?

Pour into another case and so forth.

Did any case weight contain more or less powder? and if so by how much?

Or were they all pretty much the same?

Jerry
Click to expand...

^^Case volume makes a lot more sense then case weight. Weight just a more or less accurate estimation of volume...
 
You must log in or register to reply here.
Back
Top Bottom