.338 Win mag case diameter dilema...maybe

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czscotia

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Hi everyone,
My fired brass, both Hornady and remington measures .513" dia. just above the belt.
This is just what the Hornady book says it should be, but when the ammo in new it measures
.506" dia. Is this common?? It does not resize any smaller in this area. It seems it could rattle around in the chamber and affect accuracy?? you can see the streched area in pic.
Thanks for your input.
SDC13024_zps76b100a4.jpg
 
My .300WM does the same thing. Factory brass tends to be a little undersized based on the published ideal dimensions to reduce the chance of chambering issues. It is normal and not a real concern. Once fire formed it should fit your chamber snugly and may even go slightly over ideal dimensions depending on the tolerances on your specific chamber. When full length resizing, dies usually return the brass to close to the ideal dimensions which is usually larger than factory dimensions.

There may be a little lateral movement but hopefully no headspace movement off the belt.

Fire form, neck size, reload, shoot. Has worked for me so far.
 
czscotia .......

Belted magnum cases expand quite a bit at the transition to the web. Be sure to always headspace your handloads on the shoulder, and NEVER on the belt. You may find that eventually your handloads will require a bit of force to chamber. You've already found the exact area that causes this problem. When this part of the case expands too much . . . . it happens during the reloading process - not in the chamber. Accurate FL resizing is the way to go. If you have problems with your belted calibers handloads check this out my website (below).
 
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