Initial sight in of the Piledriver in .457.
First shot low left after bore sighting.
ATN 4KPro 5x20 (one shot zero works, was not recording as i forgot the sd card, doh!)
NSA 350gr BTHP. 4300 psi fill, 4 shots, end psi about 3300 ( Note gauge readings not compared or calibrated, but fill psi set with Regman)
75 yds. ( indoor range )
20MOA Rail was needed
I will post the chrony work and the testing of the NSA 348 knurled BTHPs, 400 gr BTHP and someGriffin Ammo, (bthp 350gr) once completed.