How can I copy frames from one action to another action? I have 3D model with an "Idle" action with a gun animation action. I click on the + button new action in the Action Editor and then rename it to "Walk" action. I create keyframes, but when I check the "Idle" action the keyframes are gone or deleted.

How can I make copy frames with security from one action to another action for not need make all work for new actions?
To solve this, you just have to put the armature(bones) to POSE MODE before copying the keyframes. Then copy (CTRL+C) the keyframes and paste (CTRL+V) to other action or a new action (+ button).