I am a novice and messed up [ How to copy the weights on bone A to bone B?]

I am making a low poly model, and messed up when weight painting…

Short story:
I need to copy all weights on my left arm bones to the right arm bones, so that i can just mirror them.

Long story:
Since i don’t know what i am doing, everytime i weight something, i go into edit mode and fix the vertexes so that it animates better. So i had the brilliant idea of deleting the right arm, because then i can just copy the left arm vertexes/bones, scale X by -1 and position it.
Then i copied the vertexes of the left arm, and as anyone else would have expected, the copied weights are on the wrong side… and when i copy a bone, it comes with no weights
I tried to delete half of my mesh body and then apply mirror modifier, but then again, one bone have the weights on both arms…
There are tools to mirror the weights, so i know that if i could just copy the weights on the left bone to the right bone, i can just mirror it and it will work. But there are no tools for copying bone weights to bones… all i’ve found was armature+weights to another mesh.

Is there any alternative besides painting it all over again? At least this time the mesh is in the correct format and i sort of know what to paint and how much… but i’d rather spend time weighting the legs instead…

if you already have automatic weights applied and adjusted weights on one side

copy vertex group, mirror it, delete old auto-created vertex group, then rename copy of adjusted one you just made

“I am dead sure i checked that menu a thousand places and only saw a(…)”
or that’s what i was going to post until i noticed that the menu is not coming from a cursor, but from the down arrow below the minus…

That will help a lot, thanks!


First I wanted to post text-only reply and write about that down arrow, but then decided it will be better to show it on screenshot. Only now I see that this pic really isnt illustrating very clear how to call this menu =D so I’m sorry for accidentally making you to “check thousand places”