Imported mesh seems to be clipping on the camera side?

Hello!

I was wondering if someone could take a look and see if they could help me figure out an issue I have with substance... I've imported this mesh from blender with unwrapped uvs and seperate materials. However parts of the mesh disappear when moving the camera. Here is a photo to illustrate. Look at the buttstock, as it is the most obvious example.

Moving the camera will make that missing part rotate on the closest side to the camera.