Not a problem Greg!
These ones we used to play with .22 Rimfires, but I'm pretty sure they can be adapted
-Pop the Balloon : Take small water balloons and fill tthem with air until they're the size of a golf ball. Do some that size, more about 50% larger and more 50% larger than those. Use a foot and a hlaf long piece of kite string or fishing line and hang them from a tree branch or a target holder or whatever will keep them off the ground. Now here's the IMPORTANT PART! Make sure there's a slight Breeze! Makes the game funner & more challenging!
Big Balloons are 10 points, mediums are 25 and smalls are 50. Whoever has the most points after all the balloons are gone wins!
I'm not sure if this one'll work with an airgun but:
-What's that Song? : My dad took pieces of 3 diameter inch thick walled pipe, cut them to different lengths and hung them from their own holder. Some were 6-7 feet long and the shortest was about 9 inches or so. But when hit with a .22 each one was tuned for a different note on the musical scale. They were all painted different colors, each color corresponded to a note. Picture a vertical Xylophone or a HUGE wind Chime!
He made sheets with different tunes written out in different colored crayons. The objective was to hit each one & not miss. If you miss, it's the next guys turn.
-Chase the Rabbit : (Takes at least 2 people) Drive stakes down in the yard at varoius different ranges and widths apart, now take a good LOOOOONG piece of twine and weave it through the stakes. On the end, tie a medium sized balloon with a small weight at the knot. One of your buddies has a hold of the other end.
Stand about 10 yards away from the balloon with your back to it. When your buddy says GO, turn around & try to shoot the balloon while he's pulling it through the stake course.
-Golf Ball Races : Take a few Golf Balls and place them 10-12 feet apart about 10 yards away from your firing line and see who can walk their ball out to the burm or edge of the range first. Easy game.