weight sorting brass

[RW]

New to weight sorting brass and I have a couple of questions that I would like some help with.
In weighing 100 270 win brass that will be 6.5x06 I first trimmed to length and then weighed and the range is from 183 gr. to 186 gr. what is considered a good average for Winchester brand brass of this size?
Should I trim the brass first or any other prep before weighing?
And what would be a good average for say Lapua brass?
Thank You for any help RW

 

[dmoran]

You have a very good average to case weights, better then many. Use them all .......

 

[Martin52]

Should I trim the brass first or any other prep before weighing?
And what would be a good average for say Lapua brass?
Thank You for any help RW

Yes - trim and all other prep before weighing.
Regarding " a good average" My new Lapua 308 brass is generally in a weight range of 170gr to 173gr, with only a small % below 170 or above 173. I generally batch in 1 gr increments, so 170-171, 171-172 and 172-173.

 

[Syncrowave]

I'm no expert by any stretch but I would probably segregate it into three piles, with about 2/3 of it in the middle pile, 1/6 of it in the "heavier" pile and 1/6 of it in the "lighter"pile ... kind of the way things are distributed under a bell curve. (This is probably the way it will shake out anyway, since the great majority of your cases are probably clustered somewhere around the middle weight.) Then use the light and heavy cases for fouling shots, etc., and keep your "middle pile" together as your "better" cases.

 

[broncman]

Weighing brass is bot an accurate indicator of internal case volume.
Been discussed here many times.

 

[Immike]

I place the brass in the boxes in the order of weight and label the outside of the boxes with the weight range. For bench shooting this keeps the cases beside their next closest in the box.

 

[CatShooter]

New to weight sorting brass and I have a couple of questions that I would like some help with.
In weighing 100 270 win brass that will be 6.5x06 I first trimmed to length and then weighed and the range is from 183 gr. to 186 gr. what is considered a good average for Winchester brand brass of this size?
Should I trim the brass first or any other prep before weighing?
And what would be a good average for say Lapua brass?
Thank You for any help RW

Size and trim first, and do any other prep like coning the flash holes - then weigh.

A 3 grain spread is great - I once bought 400 Federal 308 "Match" cases and the weight ran from 155 to 176 grain, and the distribution was all over the place

Weighing brass is bot an accurate indicator of internal case volume.
Been discussed here many times.

I have had better results weighing cases. Over time, the ES and AV have been lower with weighing, than checking volume with water, alcohol, vampyre blood, or bat guano.

Lower ES and AV are what I am looking for.

 

[Shynloco]

I place the brass in the boxes in the order of weight and label the outside of the boxes with the weight range. For bench shooting this keeps the cases beside their next closest in the box.

+1...Same here.

 

[bsekf]

I agree with the Kitty Shooter, you'll drive yourself crazier trying to measure volume.

 

[dannyjbiggs]

New to weight sorting brass and I have a couple of questions that I would like some help with.
In weighing 100 270 win brass that will be 6.5x06 I first trimmed to length and then weighed and the range is from 183 gr. to 186 gr. what is considered a good average for Winchester brand brass of this size?
Should I trim the brass first or any other prep before weighing?
And what would be a good average for say Lapua brass?
Thank You for any help RW

Unless you are holding something back from us , that is an excellent lot of Winchester brass ...well on par with Norma and Lapua. Being Winchester though, you may want to do more than just "trim to OAL" before weight sorting. Might also want to deburr the inside of the flash hole and uniform it with a Sinclair instrument of same name. (Attending to the primer pocket, I'll leave up to you? And, after working the flash holes, you might inspect each one of them and cull all the still remaining mal-formed ones ???, your call!) With all the excess (although minor) brass removed, you are ready to proceed to weight sorting to the nearest grain.

Further, if you plan to use your 6.5-06 in prone/F-Class competition, you might consider going back for an addition 400 cases of this SAME lot number? Once you have run 500 cases thru the above process, you will have weight sorted batches of meaningful quantities for competition; and more than likely, you will be able to further sort the normative batch on into 1/2 grain meaningful quantities?

Dan

P.S. Before weight sorting, provided that you have the means to absolutely clean the inside of your new brass, you might also consider running the brass thru your FL die, necking down from .270 to .264; followed up with a 60-70% neck trim cleanup...DO NOT allow the trimmer into the shoulder at this time. (It's mighty important to get all the lubricants out of the neck and inside case before going to the scales...this could be a dangerous move.)

 

[RW]

Thank You for all the help on sorting brass!! I had done the primer pockets inside and out and trimmed and chamfered prior to weighing them I just didn't know what to expect for the weights? I didn't know if we were talking tenths of grains or whole grains. That is correct that there is a large middle group and smaller groups above and below the middle average group but they do weigh for the majority 185 grs.
So brass that weighs in the average of 3 or 4 grains difference is not that bad?
I will clean up the necks and I have a question, when necking down with a bushing die it doesn't size all the way down to the shoulder so when I use the KM neck expander will this even out the neck diameter for neck sizing? I was just wondering the mandrel would iron out the step in the neck?

Thank You, for your time and help RW

 

[mikecr]

The only thing brass weight in itself affects is expansion ratio.
That is, the amount of brass actually contributing to volume w/resp to the rest of the bore, once the bullet reaches the muzzle. This is too small to measure, and assuming anything from it is not productive.

Initial case volume is another matter, way more significant, but it does not correlate directly with case weight.
You have to prep brass and fully form cases to stable dimensions before measuring/comparing volume.
And if you FL size, you might as well convince yourself that volume doesn't matter(because you will never match volumes anyway).

With fast and high enough pressure peaks, FL sizing will be required, but neither brass weight nor volume variances will make any difference here. This is the big work-around for many things, and pretty much sums up underbore BR cartridges/loads(6PPC through 6.5x47).
With larger cartridges this work-around is not possible, and while brass weight still doesn't matter (once you've normalized neck thickness/tension), initial volume matters a lot. If you improve a larger cartridge so that FL sizing is not required, you can match case volumes, and you can actually measure benefits of this.

 

[dannyjbiggs]

The only thing brass weight in itself affects is expansion ratio.
That is, the amount of brass actually contributing to volume w/resp to the rest of the bore, once the bullet reaches the muzzle. This is too small to measure, and assuming anything from it is not productive.

Initial case volume is another matter, way more significant, but it does not correlate directly with case weight.
You have to prep brass and fully form cases to stable dimensions before measuring/comparing volume.
And if you FL size, you might as well convince yourself that volume doesn't matter(because you will never match volumes anyway).

With fast and high enough pressure peaks, FL sizing will be required, but neither brass weight nor volume variances will make any difference here. This is the big work-around for many things, and pretty much sums up underbore BR cartridges/loads(6PPC through 6.5x47).
With larger cartridges this work-around is not possible, and while brass weight still doesn't matter (once you've normalized neck thickness/tension), initial volume matters a lot. If you improve a larger cartridge so that FL sizing is not required, you can match case volumes, and you can actually measure benefits of this.

Thanks for the overview, Mike. I could not agree more with you and broncman: the most precise/exact means to sort case volume is water weight sorting, or whatever other liquid might be used. I will quickly use that method as a comparative for wildcat cartridge formation. But, for me, it is not practical when I feel that my shooting discipline requires mostly dealing with a "minimum" of 200 round sorted batches (and multiples of such sorted batches) that I'd like to be fairly consistent. For me to "waterboard" the quantity of cases I would need to to achieve my minimums/multiples is daunting when I can use a sensible short-cut pedestrian equivalent...not as precise/exact, but of sufficient utility to maintain decent ES's for 1000-yard prone/F-Class shooting. Respectfully, if I were a low volume BR shooter, I might have an entirely different perspective. MOST CERTAINLY, it is a sensible means to get Winchester brass to fairly shoot. Because, IMO and IME, RW was extremely fortunate to realize such a small weight sort spread among his 100 cases, and I doubt that "waterboarding" would batch them any closer together!! The suggestion that RW FL size his cases was to neck down his case necks in order to perform a rudimentary outside neck trim to further eliminate unnecessary brass from the weight sort equation.

Dan

 

[mikecr]

There are as many assumptions made with weight sorting brass(instead of volume measurement), as with nose trimming(instead of setting meplat diameters).
When you sort brass by weight, you might think they're all the same capacity, while they're not. When you separate those by weight that fall outside a band, you could be seaparating cases that actually match the bulk in volume, while keeping others that don't.
People think it 'doesn't hurt' to weight sort cases, but they could be wrong as it could be a bad move.

The only way to know volumes is to properly measure it. There is no shortcut(other than using powder or something instead of H20).

 

[ronemus]

I did an experiment several 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. I choose to sort 0.5 gr lots of .223 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. I also shoot .284, and because the brass is twice as heavy I batch in 1 gr lots.

 

[bigedp51]

I have had better results weighing cases. Over time, the ES and AV have been lower with weighing, than checking volume with water, alcohol, vampyre blood, or bat guano.
Lower ES and AV are what I am looking for.

Catshooter read this posting I found even more bat guano.

The only bigger waste of time than weight sorting brass is reading a thread in which people advocate weight sorting brass.

http://forum.snipershide.com/snipers-hide-reloading/233095-weight-sorting-laupa-brass-necessarry.html

It's deja vu all over again............