Walther pdp 4 inch steel frame July 8, 2019 16 32 64 128 Walther pdp compact steel frame 4 inch Walther pdp compact steel frame 4 inch specs Walther pdp compact steel frame 4 inch review Walther pdp 4 inch Walther pdp 4 Walther pdp 4 vs 4.5 Walther pdp compact 4 inch review