How do you go about animations for multiple weapons in first person shooters?

Hi there guys,

I've been asked to work on a first person shooter, and to be honest I've never worked on such a project and am a bit lost.

The thing that I find difficult to figure out is how to go about the animations for holding, reloading, etc ~ multiple different weapons of different sizes and dimensions. It seems like a bit of overkill to have a different animation for every single weapon. From what I understand, people instead use IK to place things where they want them. So how exactly does this work? Do you need some generic weapon handling animations that you override parts of (such as the hands, arms and elbows) with the IK? Like say an assault rifle animation that can be reworked to hold rifles of different lengths?

I've searched all over but haven't found anything particularly concrete...

I'd really appreciate any advice on this topic!