Looks like you could throw the rifle and hit the ballons. ETA:
Try 8" round paper plates on surveyor's stakes. I'll drive down my favorite shooting range and set them up at random distances out to several hundred yards, park the truck at the far end of the sting and start in on them. At 600-800 yards I'll "cheat" and use a bolt action with a range finder. The stakes are 3' tall so they serve as a good estimate.
After playing with the bolt action I'll come in using an AR working the targets prone, kneeling, and freehand. Once I get close enough to some I'll use the pistol on them. I carry spare ammo, water, and patching tape in my ruck. I can work the same 15-20 targets all day long coming at them from different directions.
I also have two 18" and on 12" rifle gongs that are fun but much beyond 300 yards it's hard to hear them ring without using my electronic hearing protection and waiting for the ring.