Brass weight range

[jonk]

When sorting brass by weight, what variation is acceptable? For .223? 30-06?

For instance, looking at some Lake City .223, I notice a range on the cleaned sized cases of 88 to 96 grains- quite a variation. But should I go for all one weight (really anal) or say 1-2 grains variation? 2-3?

[Wayne Smith]

I wouldn't do anything until I knew my accuracy with the existing variation. Then look at the other variables and how much influence they may have vs case capacity. I'd guess you are looking at a very minor amount of variation in case capacity. If you are as OCD as that you might check those cases on the extreme of weight and see how much they vary in case capacity. That is really the variable that matters.

[Doc Highwall]

I could give you two different answers depending on your use for them. Take the 223 brass for instance, if you are shooting it in a AR that has been used for rapid fire plate matches and has had a lot of rounds through it I would say just shoot them and not worry about anything. Now if you had a masters or high masters classification and was shooting them in a match rifle with a good barrel I would say weigh them. For a case the size of a 30-06 I would keep them within 1 grain and for a case the size of the 223, I would keep them within 1/2 grain. Actually it is like comparing a 45 caliber 500 grain bullet to a 22 caliber 50 grain bullet with a 1% weight variation, easy for the 500 grain with a 5 grain tolerance but only .5 grains for the 50 grain 22 caliber bullet. The scales most of us use are only good for + or - one tenth of a grain and when this is combined with a small case like the 223 or smaller like the Hornet a small variation in powder charge combined with a larger case weight variation add up to higher extreme spreads of muzzle velocity.

[mike in co]

how big is the lot of brass ??

almost all of my rifle brass is weight sorted.

some lots are plus or minus 0.05...no that is not a misprint.
most are plus or minus 0.5 or less.
these are anywhere form 20 to 60 pc lots...but started as 500 pc lots.

it all depends on what you are doing.

cast boolit plinking...could be as big as plus or minus 1 for larger rifle.


you told us caliber you did not post end goal.
i shoot 50 rd 100yd and 20 rd 200yd mil rifle matches, and 10/20rd br matches .

mike in co

[montana_charlie]

For instance, looking at some Lake City .223, I notice a range on the cleaned sized cases of 88 to 96 grains-
Your wording implys you are not working with new brass.

When weighing new brass from the same lot number, I will divide into three groups called light, normal, and heavy. The 'normal' cases will number in the definite majority, and I will set a +/- limit based on how many there are.
The method simulates using a bell curve, but I don't actually plot one out.

From a batch of 250 new 45/90 cases, I ended with 150 that made up my 'normal' grouping. There were 35 which weighed 'light', and the remainder are in the 'heavy' sack.
In the end, the cases in each group all weighed the same, plus or minus a half-grain (a one-grain spread) after I decided where to draw the line.

Coincidently...
I decided to use 30 of best-matched 'light' cases strictly for load development, and alternate them in two fifteen round batches.
After loading a batch one time I decided to weigh the loaded rounds, to try out a new digital scale.
Yes, I am careful to weigh powder charges, and I also match bullets by weight when developing loads...but I don't weigh wads, primers, or bullet lube.
Those fifteen rounds all weighed within a half-grain of each other.

Strangely, they did not all shoot within a half-inch of each other.

I can't imagine where the problem might have been, but at least I couldn't blame it on the ammo...

CM