Brass weight.

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bobjoe

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I am not new to reloading but I am new to precision reloading. Ie I am starting to load 338 lapua for long range shooting. Part of this is weighing brass. My question is how much variance should I allow with the weight of the brass. For example. The lightest brass so far is 328.2 grain and the heaviest is 331.7 grains. To me this doesn't seem like a big gap but I am new to this.

Many thanks in advance for the help.
 
The first time I reload a batch of brass, I weigh it and discard any that have a weight that's much higher or lower than what seems to be an average. This is primarily for hunting ammo. If there's a calibre I'm loading specifically for paper punching or especially for some longer range target work, I'll narrow down that weight spread even more. I do much the same with bullets.

My son in law recently had a custom 300WSM made up and I reloaded a sizeable quantity of ammo for him, using the 'recipe' of the builders test ammo. He has plans for some longer range shooting and hunting planned for that rifle so I did a quick check of brass and bullet weights, looking for any major differences in weight. Then, I divided up brass and bullets into two individual groups, basically one half over a mid weight and those below in another, just to minimize inconsistencies and variables.

From his use of the rifle hunting this year it sounds as though 'things' worked out well. Three Deer with three shots at quite a wide difference or variety of ranges.
 
By no means am I an expert here but I was always under the impression that it did not matter what the cases weighted but rather what they held for weight that is important. I was told to fill them with water and then weight the water. Again this is just what I read somewhere.

Graydog
 
graydog said:
By no means am I an expert here but I was always under the impression that it did not matter what the cases weighted but rather what they held for weight that is important. I was told to fill them with water and then weight the water. Again this is just what I read somewhere.

Graydog
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Me either. It just seems that if there is a significant difference in case weight, and the outside is resized to a standard, the case capacity must be effected. Again, I do what I've explained previously, for consistency. I believe, the greater the variables, the greater room for inaccuracy. ;)Plus, if nothing else, consistency for me promotes confidence.
 
With the size of 338 lapua case I can't see 3gr difference in brass weight making a huge impact.

On a much smaller case the weight difference would be more likely to change things.

With a 308 sized case I weight sort into 1gr increments, the same with 6BR cases. With cases such as 223 I sort into .5gr groups.

Now I sort because I use these cases for competition, I don't bother with my hunting brass.
 
Tony Boyer sort his 6mm PPC cases in groups of 0.1gr increments.
He would probably sort his 338 Lapua Magnum cases in groups of 0.5gr increments ;)

Alex
 
AlexF said:
Tony Boyer sort his 6mm PPC cases in groups of 0.1gr increments.
He would probably sort his 338 Lapua Magnum cases in groups of 0.5gr increments ;)

Alex
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Yeah, but he only needs 20 cases for an entire season of shooting.

When you take 300-600+ rounds with you for a match you would be purchasing many thousands of pieces of brass to cull it down to .1gr increments.
 
I segregate into groups having one or two grains variation. With 100 rounds I would really like to have 50 that show the least variation. Those that are really heavy or really light can be used as fowlers or put into a box of bullets to serve a "indexers" which were seated to the lands.
 
That sounds pretty consistent to me, 3.5 grs for that case.
Two ways to go about it, split them and go light and heavy as mentioned or go average +/- 1 grn in this size of case. Is the rifle capable of shooting 1/4 moa? If not just load them all and shoot, as 1% is a very acceptable variance. I sort my 22-284 to nominal average +/- .5 grn so all my brass falls within 1 gn weight. Don't know if it helps but makes me feel good, and someone told me to do this if I want to shoot 2" groups at 500 mtrs. Besides I far prefer spending time in my loading room that listening to the wife, and I'm certain it doesn't hurt.
I then relagate the over and unders to two groups for my 6mm-284.
 
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