Gun Modelling Question

I want to add a reloadable pistol in my Unity game. Do I need to model the whole gun apart from the magazine or do I model the gun magazine WITH the whole gun?

Im sorry for asking so many questions, I’m new to modelling and unity.

Moderators, if you are going to close this post, could you guys at least send me a link to a similar post where there is answers?

Create them separately. Otherwise you couldn’t change the mag.