I recognise this gun system. This is @doser225’s work that comes from a leaked copy of a game called Area 108. A bit of a shame to be asking for help on fixing something you didn’t make.
Gun animations are natively supported by that system and don’t require any script changes. What you’re most likely doing is uploading animations with the wrong properties. Don’t loop the animations and keep them at a higher priority to prevent overwriting.
Roblox animations use the lowest priority with Core and the jump animation uses third priority, Idle. All your animations then should be using a higher priority. If I recall correctly, the hold animation should be using the Movement priority, while the recoil and reload animations should be using the Action priority.
The fix @wiidoot provided will work to stop the current animation since the source code loads a different AnimationTrack and stops it instead of stopping the same one, but it does not fix any of the overwriting issues.
@colbert2677 Sorry I didn’t know this gun system was stolen from one of your friend’s work, what I could do to make it up is immediately disband this gun system and find another script that is similar to this that is created by someone else.