Brass weight difference

[coupalr]

Just wondering, when you guys weigh your brass what difference do you consider allowable. The last batch I sorted I came up with 30% that were within 0.3 gn. Should I widen my tolerence? By the way, these are Nosler seconds.

 

[Bart B]

A one grain spread in case weight is good enough. Most primers (especially 'magnum' ones) have a greater spread in ignition properties that will change muzzle velocity more than a three grain change in case weight.