You can try working up to 82gr's of RE25, this is MAX for 180gr pills.
Keep a close watch on bolt lift, any sticky bolt lift is a sign of excessive pressure.
I found that RE25 was the most 'trackable' powder in the 300WM, very uniform pressure and velocity readings, I was unable to get enough in the case to get beyond MAX pressure, but got a true maximum pressure and 100fps more velocity out of it.
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