Neck sizing question

[gamma]

The neck of my chamber is .310, or at least it should be as thats the size the reamer was. Its a 7mm wsm. My question is, what size should I be sizing the necks on my brass. Im new enough to reloading so Im only just finding my way.

 

[groupshooter22]

What size does fired brass measure? A loaded round? You should size them about .002-.003 under loaded round dia.

 

[Ram]

What size does fired brass measure? A loaded round? You should size them about .002-.003 under loaded round dia.

Most sources recommend 0.002" - 0.003", but Redding now says 0.001" instead of the 0.002" - 0.003" they recommended previously.

 

[kitsap]

There is no one right answer. A different cartridge - bullet - powder combination will respond differently to neck tension. If you are neck turning your brass you will get the full benefit of the neck sizing die when you do not pull a sizing button back through the brass after neck sizing. Most of the numbers quoted are starting points. If your accuracy is acceptable no need to change. If not, one of the variables you can change is neck tension. Also as the brass work hardens from reloading, the resulting neck tension will change for a given sizing diameter.

DougF