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Posted: 11/28/2010 4:46:59 AM EDT
| When you diehards weight sort your brass, what's your threshold for your selection? +/- how many tenths of a grain |
| 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 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. For my .284 brass I sort into 1 gr lots since the case weight and volume are approximately doubled; I'd do the same for the '08 and '06 family of cartridges. |
| I go +/- .5gr with my medium caliber target rifles and +/- .3gr with my 6mm BR. I bought some Lapua .223 when I had a m700 varmint rifle and they were all within +/- .5gr out of the box. I also use Lapua in my .308 and 6mm BR. To bad they don't make it in 6mm Rem. I get about 65 out of 100 winchester cases within my weight range. |
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Quoted:
Unless you control all other sources of variation, the effect of brass weight is negligible. Bingo! If you are just sorting cases by weight and not separating by headstamp, using match bullets, accurate rifle, trickling powder charges, etc, ronemus is right. It's going to be a waste of time for 223. |
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Quoted:
Quoted:
Unless you control all other sources of variation, the effect of brass weight is negligible. Bingo! If you are just sorting cases by weight and not separating by headstamp, using match bullets, accurate rifle, trickling powder charges, etc, ronemus is right. It's going to be a waste of time for 223. Yes––MANY other factors have a far greater effect for the average (and above average) shooter. It's only worthwhile for bench rest shooters. I view it as a "if you have to ask, you don't need to bother" kind of thing. Those who will benefit from it already know about such things. 
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