I'm a varmint shooter now, hitting crows or chucks at 400 yards is a different game than 1,200 yard shooting but I've done enough of that. I'm on the side of decent groups but hyper velocity.
For example my 223 for crows and chucks will shoot 2.5" at 300 yards with 55 grain varmint projectiles @ 3,100 FPS, slightest wind bounces them around. When the wind kicks up that can spread to 3.5" to 4", gusts to 35 to 50 MPH hurt you hunting.
I went with a custom load, Malaysian military brass gets me 2 grain more powder, a 40 grain moly coated varmint projectile now at 3,900 FPS reduces time in flight, 1.1/8" @ 300 yards spread to 2" in the wind.
Real windy days I'm on a 6mm Remington with 75 grain moly projectiles, @ 3,900 FPS, 1. 1/16" 300 yards and stable up to 50 MPH winds.
Reduced time of flight, long range work many years ago I tested to 300 Kong!