I shoot local f-class matches in my area. I hang out with a few guys that just made the US National F-Class Team. Sure you can see targets at 1k. We even hit them from time to time. As for subsonic at 800 That's odd, when I work the pits there are plenty of sonic cracks as the bullets go over head. If you load the right bullet with the right powder you can keep a 308 super sonic to 1k.