This is for my Lyman Great Plains 54 cal. 32"Bbl. , 1/60 twist. Shooting the Lee 300gr "REAL" bullet. Charge is 80 grs, Triple 7 FF. Just wondering if anyone might be able to venture a velocity. I'm dead on at 50 yds , & 5" low at 75yds. Also, this sounds stupid, but I did not think to shoot...