My best success with the 95 gr. FMJ round nose projectile from RMR Bullets is with 5.0 grains of Hodgdon HP-38 in a one-port, 4 inch barrel on a Hellcat 9 mm, shot off a sandbag at 12 yds. It produced a one large 10-shot hole of approximately 1.5 inches. I got similar results with a green dot laser.
I got approximately a 2 inch pattern with 4.5 gr HP-38, and approximately 3 inch pattern with 4.0 gr HP-38.
I almost forgot to mention that I cheated — I was using a Red Dot sight and the target was not shooting at me!!
