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/VH
04-09-2009, 09:26 PM
What is the proper sequence for performing case prep and sorting on new brass? Is it best to size, trim, chamfer, de-burr, ream flash holes and uniform primer pockets prior to sorting brass by weight? Which is more critical for accuracy, uniform weight or uniform neck wall thickness? Will uniform neck wall thickness and uniform weight generally correspond with each other? What are the generally accepted weight and neck wall thickness tolerances for Winchester and Lapua brass for a standard (not tight necked/no turn) chambering.
Thanks for any and all replies.

JerrySharrett
04-10-2009, 07:42 AM
What is the proper sequence for performing case prep and sorting on new brass? Is it best to size, trim, chamfer, de-burr, ream flash holes and uniform primer pockets prior to sorting brass by weight? Which is more critical for accuracy, uniform weight or uniform neck wall thickness? Will uniform neck wall thickness and uniform weight generally correspond with each other? What are the generally accepted weight and neck wall thickness tolerances for Winchester and Lapua brass for a standard (not tight necked/no turn) chambering.
Thanks for any and all replies.
Just a few remarks. If you are making benchrest cartridges and using Lapua brass you will not have enough weight variation to be a factor, this also goes for flash hole diameters and primer pocket depths.

The flash holes are drilled and some cases need to be deburred in the inside. In doing that use a tool that will allow you to control the chamfer, not in diameter but in keeping the straight part of the flash hole consistent lengths.

The neck wall thickness for the virgin product will be close also. That is not to say you can't screw it up yourself in the neck turning process.

As to the neck turning process you are not going to have a concentricity problem (OD to ID) but you can effect accuracy by having over about 0.0003" variation in neck diameters case to case. Variation in neck diameters effect two things, first, neck tension variation, and second, neck to chamber clearance variation which effects pressure rise.

abintx
04-10-2009, 08:50 AM
Since you seem to be interested in sorting and didn't mention whether you're a long range or short range aficionado, here is one approach used by a Long-Ranger :D with some nice pictures: http://www.6mmbr.com/jgcaseprep.html

/VH
04-15-2009, 09:26 AM
Thanks for the replys. Art the link that you provided was very interesting and enlightening as far as different considerations that should be taken into account for long range as opposed to short/medium range. My intention was just to cull brass for hunting calibers in SAAMI chambers and avoid neck turning. I don't know if it will make any detectable difference in these rifles but I have sorted some brass by neck wall thickness variation and weight variation and hope to catch a day with little wind to see if I can tell any difference.