So I've been trying to find for a while a good bag to use to carry around ammo and managed to find these Hungarian gas mask bags from this army surplus website I've used a lot.
https://www.supernova.fi/product/4242/unkarin-armeijan-puuvillainen-kaasunaamari...It is all in Finnish I'm afraid but basically they are pretty much perfect for slinging. They are also selling them in pairs so I now have one surplus to requirements
I haven't tested out them out extensively as they only arrived today but they seem to be hard wearing enough and have both a shoulder and waist strap so the weight of the stones inside them is well distributed. I managed to fit around 7 or so fist sized stones and though I could feel the weight it didn't feel cumbersome.
So would anyone be interested in my spare one? Does anyone have a sling perhaps they wouldn't mind parting with?
The measurements are 32cm x 17cm x 12cm.
I can post additional pictures of the exact bag if it's required.