I've been thinking I need a set of bags made from the legs of an old pair of pants.
Reading this post gave me an idea for fill. I like the sound of plastic pellets, but could be expensive. What about buying stuffed animals or bean bag chairs from Value Village or a local thrift store?
Sometimes the fill is those little plastic beads, drain them into your empty shooting bags.
I may just raid the kids' "stuffy" section at the local second hand store, they usually have a huge bin of donated critters. From time to time they have a "Stuff a bag for a buck" sale, Drain the beads out, re-stuff with some old scraps, then use the critters for targets. Recycling at it's best!