Sorting Brass by weight

[Subsonicwarthog]

I just went thru 100 peices of 300WSM Norma brass and weighed each one and marked the weight. I have over 26 different sorted weights of brass in .01 increments. They have been length sized
and I do not know the standard used to group them by weight. Do you keep them in 1 grain groups or 1.5 grain groups? Thanks for your help in advance.

 

[Forum Boss]

Are you saying you sorted by 1/100th of a grain?

If so, that would be overkill.

Or are you saying you sorted by 1% weight variation? That's much different.

Others may differ, but I'd probably group the brass in half-grain increments, and see how many divisions you then have.

 

[mikecr]

IMO, your efforts in sorting by weight are of little use.

Why not sort by thickness variance, fully prep your best brass, then fireform it, and finally, measure and sort by H2o capacity?

 

[ronemus]

I did an experiment a couple of years ago to determine just how much effect brass weight has on .223 loads. I used WW brass,sized, trimmed and deburred, primer pockets uniformed, flash holes deburred, and neck turned), WSR primers, charges of RL-15 or N-550 powder weighed to 0.1 gr, and 75 gr A-Max bullets. Using the lightest and heaviest cases,sorted from 1000 once-fired I had on hand), I had two lots of 10 cases with a 3 gr difference in weight. The average muzzle velocity difference was 16 fps, just a bit more than the 12 fps due to 0.1 gr of powder. The effect would be reduced in larger cases. I choose to sort 0.5 gr lots of brass for my long range loads, but the effect will only matter at 800-1000 yards - the vertical displacement on the target from such a small velocity change is negligible at shorter distances. Unless you control all other sources of variation, the effect of brass weight is negligible.

 

[StephenPerry]

Sub
Why weigh anything especially for a 300 WSM. I buy 100 brass from Ron Hoehn all the same weight but even my stakes are higher than yours I could be happy with brass out +/- .3-.4 tenths. I shoot 22 & 6 PPC in short range BR the ultimate in the grouping machined guns. But allot of guys today are trying to up their ante in the accuracy game. You didn't waste your time most accuracy reloaders have weighed cases before.
My advice is fire form each case 2 times with stiff loads bullets in the lands and trim all to a specified length. Next time instead of weighing cases clean your gun.

Stephen Perry
Angeles BR

 

[ronemus]

Velocity variations don't afect external ballistics at short range, but at long range,>800 yards) they become critical. A 50 fps variation in velocity can mean >1 MOA increase in group size. That's significant, considering that the X-ring in NRA Long Range is 1 MOA at 1000 yards, and that winning 1000 yard BR groups are <1/2 MOA. That's why long range competitors of all types pay attention to velocity spreads.

 

[AckleymanII]

If you guys want to sort brass, sort them by the amount of thickness in front of the Web,run out).

 

[Lane]

Are your dies producing a case that fits your particular rifle chamber? You can sort cases by weight, prep primer pockets, neck turn, neck size your brass,play with bullet seating depth use what ever so called match prep or sizing method you what to! To take advantage of any of the so called match prep or sizing methods you first must fit the case to your particular chamber. If the case is misaligned in the particular rifle chamber what good will any of the methods do? take the critical case/chamber measurements first. Understand if your particular dies are building a case that fits your particular rifle chamber. You will then know if you can take advantage of any sizing method or match prep methods, bullet setting depths. Personal point of view. Best wishes Lane