I am preparing to sort brass by weight for my 6.5 Creedmoor.
What is the standard +/- weight deviation for culling brass?
How much weight spread can you in a group of brass and still call it acceptable?
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I am preparing to sort brass by weight for my 6.5 Creedmoor.
What is the standard +/- weight deviation for culling brass?
How much weight spread can you in a group of brass and still call it acceptable?
i would be asking myself what my plans are for my shooting. if your a hunter and casual shooter who also enjoys shooting "decent"
groups i wouldnt be doing anything but load the brass. theres almost no end to what you can do in the quest for accurate loads.
weighing and sorting match bullets could be done also. then you could buy a tool for trimming the tips of the match bullets so that
their all uniform. trimming the megplates would be the term. these things are usually only done by serious competetors. but not always
i guess depending on the individual. im of the opinion weighing and water volume would answer your question however.
Brass weight is not so much the issue as the internal volume of the case. You can have way different case weights but have the same case volume which will produce the best shot to shot consistency. Full length size and trim every case, re seat some used primers to seal the case then weigh each case to get an empty case weight. Next fill each case with a water dropper and scrape off the excess with a credit card so that the water is flush with the case mouth. Then weigh the case again. Subtract the full weight from the empty weight to get the case volume. You will probably end up with three piles of brass, one large pile that weighs the same and then a smaller pile that weighs the same and then a small pile that really doesn't match anything. I allow .1gr above and below a median weight which will become apparent as you go along. Hope this helps.
Unless you are an excellent sub-sub MOA shooter it probably won't matter much compared to all the other easy things you can and should do first.
I would start off by separating by whole grain increments and see where that takes you. Some brass is all over the place, and some is quite consistent. I only weight sort brass for my long range gun (1000 meter).
I weight sort before I do any brass prep work.
I don't shoot that caliber myself, what brass do you have? Nosler? Hornady? Not sure who else might make it?
I do this for every rifle I own as I try to eek out every bit of accuracy I can as its either a bench gun or a long range hunting rifle. The process takes time but it is well worth it. I will give you an example of a time I was helping a buddy do some load development for his .243. He was holding about a 3/4" 5 shot groups at 100 yards with 85 grain sierras and winchester cases. I asked him if he had sorted his cases and he said no and had no experience with the process so I invited him to the house to give him a run down of the procedure. We sorted 100 cases and when we were done we had about 60 cases that weighed within .2gr of each other and another pile of about 25 cases with a different volume within .2gr and then another pile of brass that just didn't fall into any pile and was just inconsistent all around. To make a long story short the same load he was using before is now shooting well under 1/2" at 100. Sorting by volume can do great things.
Volume is what matters. Weigh some and check the volume on those at the extremes; then load them and see if the POI is different at the longest distance that you can. If the POI shifts in correlation with the volume then it may help you.
I sort my hornandy brass into two groups. There's usually a group that runs around **50-51 gr and another **48-49 gr. There must be two separate machines that get packaged together.
The right way to do it is by checking internal volume as mentioned.
Neither is necessary to achieve .5 moa but if you want to get under .25 moa you better check everything possible .
I also shot Hornaday brass and have experinced the same weights that you have.Quote:
Originally Posted by limige
After loading, have you chrono'ed the different weights to see how much it can change in FPS?
Upon purchasing a batch of once-fired NATO brass for my 223 I segregated based on year for the LC, and three other brands. Weights were very different for the various manufacturers, as well as typical variability within a brand. Water capacity was not so different, and the POI at 300 yards identical regardless of anything. Now I mix all years of LC, but do keep the other brands separate just as a matter of good practice. This is not to say weight or more importantly volume does not matter, especially for different calibers. But I think you should validate the segregation for any parameter based on range performance to make the long-term effort worthwhile, and focused on what matters for your particular case.
Stroker I have not yet. I will be building a home range shortly and will get more in depth on it all. I'm curious how much the internal capacity varies with weight and whether or not they truely correlate.