I made up a 50 yard plinking range behind the house with targets every 10 yards to check the trajectory of any given pellet and made up a modest little spinner for each target - 3/8" @ 10 yards up to 1-1/4" @ 50 yards.

Backyard range:


40 yard spinner (7/8"):


I started doing 100 yard shots for fun and (growing up on a farm) found that a small to medium size cow bell hung from a branch makes for a great reactive target at longer distances. No problem wondering if you hit your mark or not - "ding-a-ling-a-ling"!!!...

Cheers,
Todd