I think it might. https://www.amazon.com/gp/aw/d/B003WWOLRQ/ref=ox_sc_saved_image_1?smid=ATVPDKIKX0DER&psc=1

IIt's a possibility,  but u can go cheaper.  Use either jumbo marshmallows,  or rolled up socks. The perfect indoor ammo, and soft enough, to have have sling battles like dodge ball.

I've seen squash balls used as indoor ammo (I can't remember which user suggested it... sorry!) but I don't have any experience with them myself.

same weight as regular lacrosse ball - So not suitable for indoor, unless you're in a gym, like jaegoor uses.

In einer Turnhalle funktionieren rusty Bälle sehr gut . In der eigenen Wohnung besser nicht. Auch gut für drinnen sind diese Bälle.  https://www.amazon.de/V3tec-SPORT-2000-DEUTSCHLAND-80g/dp/B01H7H5W1A

Thanks for the info guys, I was planning on using them in a gym, so from what y’all have said they seem good. As for the rusty balls, they seem really good, but I would be afraid of one of them bursting and making a big mess  ;D.

Weight plays a pretty big part.  Anything that weighs much more than a sock will go through a window like it was open, and clean stuff off shelves like it was in a bowling alley.

Even a tennis ball can knock you rolling.  They hurt.  Not breaking bones hurt but bad enough that you don't want to play anymore if you are on the receiving end.  Some form of armor is very helpful and you should really have head and eye protection.

The phrase: 'Jaegoor's Rusty Balls' always makes me grin :-)

They're actuall;y quite expensive to make - but if you make them like he does, with 10 or more balloons. They are really tough.

Just bear in mind that you are slinging, what is essentially, a handle less cosh. Cosh's are illegal in most countries.
So while rusty balls are great - they are also potentially lethal.
 

Ja das stimmt rusty Bälle sind tödlich.  Aber teuer sind sie nicht .
Safty Bälle fertige ich so.
https://m.youtube.com/watch?v=suwLfksonh4