Re: 0.02" expansion on 264 WM brass
.020" is not unusual in a belted case and most of my guns average that
Here is an extreme case
That's almost .040" and probably would have reached that in a couple more firings
That rifle got rebarreled because IMO there would have been too much initial stretch at the pressure ring even if subsequently headspacing off the shoulder. On all of my other belted case guns that average .020" I haven't had any problems with case head separations or anything else.
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