I often use this adapter:
https://www.thingiverse.com/thing:6368674?ysclid=mcoinezlvl912743921
But have one problem - “How to pour bbs from a bag into a bottle without scattering them?”
Then one guy saw it and asked me “Why you don't print funnel for it?..”
It was good idea! I designed and printed this thing. It turned out to be incredibly convenient!
Recomends this thing all body who uses bottles for storing theirs bbs.
Have fun and good luck in games!
The author marked this model as their own original creation.