FWIW, my go to 77 SMK load is 23.25 grs of XBR, that said my 69 grain SMK load is 23.90 grs XBR, so maybe the 73 grain was off node for you, and a little more enthusiasm behind the lift off would be a benefit? Mostly I run the Fed 205 Standard primers now that my beloved Wolf supply has nearly come to an end. I have no doubt that you know what you are doing and you know your rifle, but perhaps trying a ladder in this barrel might be beneficial.
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