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Old February 8, 2013, 06:12 PM   #9
Join Date: March 4, 2005
Location: Ohio
Posts: 11,390
Unfortunately that chronograph method is not safe with surplus bulk powders. They vary enough to act like significantly faster or slower powders on a powder chart would do. It's therefore possible to go well above healthy peak pressures with a new lot number when trying to match your previous lot's velocity. This is one reason for powder lot rejection by the military: when that lot can't reach their velocity window inside their pressure window. There's a good description by a former Aberdeen Proving Grounds Test Director in post 25, here.
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