If they spawned with a firearm in the world. Then they continually rack and or exchange magazines. Only way to stop it is to give them melee weapons, if they don't have one, if they are your companions/group. Once told to switch to guns they start this behavior again.

Wasn't always like this in the play through. I am not sure what happened to cause this. Other then i would rack a around when i had jams or to get them to stop not shooting and just standing around.