It seems indeed that all animations are managed by the model_hand.md3. Basically, it doesn't involve any bones, but simply Empty entities named after tags. Keyframe their positions accordingly to the original parts of the models. For example, the Repeater has three Empty, named tag_barrel, tag_flash, and tag_weapon. Only them, apparently. The animation is made of 15 frames where they move around, and probably the actual model parts moving is managed in-game. Now to coordinate all of that with the .md3 parts and those weird angles is another matter entirely... Also, I don't know if that's important, but always check that the tags are set with Quaternion angles. Those turbolasers are actually .glm models. And the entities in that map itself are misc_turret with turbo spawnflags - they work pretty well, but only after they've been assigned a target through scripting.