Changing child issue type on self made issue type

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Hi

I want to create a issue type called "Feature". 

The hierarchy would be: 

1. Epic, 2. Feature, 3. User story, 4. Task, 5. Bug

Is it possible to change the standard child issue on my self made issue type "Feature" from "Sub-task" to "User story", as I like to work with projects that have multiple features instead of having many epics. 

Can this be done?

Thank you in advance

Best regards

Filip