I always zero for 50 yards with 22s. I always use iron sights though. I did have occasion to shoot at 315 yards at a steel man target though. A couple shots to determine holdover is all it took and then I was hitting it everytime. It didn't seem to take a whole heck of a lot of holdover, but I was shooting downhill and I'm sure that helped it.
"Always place your clothes and weapons where you can find them in the dark"
"Understand that the enemy is not the enemy in his own eyes ;this may offer you an opportunity to make him your friend. If not, you can kill him without hate, and quickly."