Armature glitch

I’m trying to give this revolver model I’m using a single bone so that I can use it in pose mode. But for some reason, certain parts of the mesh aren’t moving with it when I move it around after parenting the model with the bone.Screenshot 2021-02-02 133701

How did you parent it?

Recommended: select the revolver (all objects composing the revolver, if there are multiple), shift select armature, pose mode, select bone, ctrl-p ->bone relative.

It worked, thank you so much, it really helped.