Air Gun "Overflow" Backstop?

[Gwhite]

I have a commercial air gun backstop that works just fine, but it's no bigger than the targets. I would like to allow my daughter to use it, and she's just learning. I want to put something up behind the backstop in case one gets away from her. I'm hoping this will be a rare event, but for the sake of safety. the wall, and the stuff around it, I think an emergency backstop would be a good idea for a while. I'm assuming this will be a temporary thing, so I don't want to spend a lot of time or money doing anything elaborate.

I know Homosote (~ 1/2" thick solid gray cardboard) is too hard, and that pellets can just bounce off. Presumably a LOT of layers of corrugated cardboard would work, possibly with a plywood backer. Scrap fabric or carpet scraps in some combination might work as well.

Does anyone have any experience with a tidy solution for this? Unlike a regular backstop, it won't have to survive continuous hits in a small area, just stop the rare stray shot.

Thanks!

[Misny]

How about a piece of carpet hung away from the wall?

[jak10x]

Pellets in most cases will go into the Homasote and not bounce. I have tried it with with 3-4 different AP guns

John