by bladeracer » 11 Oct 2021, 3:33 pm
Using your figures I get similar numbers - 81m, 105m, 127m, 147m, 167m.
Shoot groups at 50m, 100m, 150m and 200m, measure the trajectory, then calculate backwards to determine an accurate BC, assuming you have measured the muzzle velocity.
Beyond 300m, groups open up enough to make bullet drop measurement less than precise, but I believe my BC is reducing slightly past that distance. A 10mph wind speed from behind or ahead is enough to add or subtract about 80mm on the height of the bullet impact at 300m.
With CCI Standard Velocity in my 18" RPR I'm using this. Basically, from a 100m zero, bullet drop is 400mm (16") at 150m, 1200mm (4-feet) at 200m, 2400mm (8-feet) at 250m, 3900mm (13-feet) at 300m, 6000mm (20-feet) at 350m, 8300mm (27-feet) at 400m, 11300mm (37-feet) at 450m, 15200mm (50-feet) at 500m.
With my RPR .22LR with CCI SV I'm using this, but I'm zeroed at 100m, and I'm using minutes:
17.5m zero 10mph wind 1.1MoA
25m 31mm 4.25MoA high 10mph wind 1.3MoA
50m 90mm 6.25MoA high 10mph wind 2.0MoA
75m 80mm 3.75MoA high 10mph wind 3.0MoA
100m zero 10mph wind 3.75MoA (200yd dot in the 223BDC is at 110m)
125m 160mm 4.5MoA low 10mph wind 4.5MoA (300yd dot)
150m 395mm 9.0MoA low 10mph wind 5.25MoA (400yd dot is at 143m)
175m 710mm 14.0MoA low 10mph wind 6.0MoA (500yd dot is at 162m)
200m 1130mm 19.5MoA low 10mph wind 6.75MoA (top of the duplex post is at 182m)
225m 1630mm 25.0MoA low 10mph wind 7.5MoA
250m 2220mm 30.5MoA low 10mph wind 8.25MoA
275m 2940mm 36.75MoA low 10mph wind 9.0MoA
300m 3740mm 42.75MoA low 10mph wind 9.75MoA
325m 4650mm 49.25MoA low 10mph wind 10.5MoA
350m 5700mm 56.0MoA low 10mph wind 11.25MoA
375m 6850mm 63.0MoA low 10mph wind 12.0MoA
400m 8130mm 70.0MoA low 10mph wind 12.5MoA
425m 9600mm 77.5MoA low 10mph wind 13.5MoA
450m 11100mm 85.0MoA low 10mph wind 14.0MoA
475m 12800mm 93.0MoA low 10mph wind 15.0MoA
500m 14700mm 101.0MoA low 10mph wind 16.0MoA
Practice Strict Gun Control - Precision Counts!