Gongs at even intervals like 100, 200, 300, 400, & 500yds.
Shooting them with steel core ammo in the evening or at night w/lights is a lot of fun.
The steel core makes a lot of sparks when it hits the gongs so you know if you have hit or not even before you hear the steel gong ring.
If everyone is thinking alike, then somebody isn't thinking. George S. Patton
The operator I work with built an AR-15 a few months back and, although I hate to admit it, it was the first one I had shot and it is scary accurate at 300.
First mag I put through it was at an 8 inch gong and I hit it 28 out of 30 shots at 300 yards. (I like shooting gongs for fun shooting).
We also shot at several travel size shaving cream bottles with his m&p 15-22 at 200 yards and it was surprisingly accurate. Never stretched a .22 that far before.
But as I said I like the gongs, miscellaneous exploding targets such as tannerite or shaving cream and water bottles, paper, and a buddy of mine works for a place where he can get manicans and hard styrofoam heads.