How can I fix my problem with mesh colliders??!!!

Mesh colliders are clunky and inaccurate! There are always too small or too big, there is no happy medium! My characters weapons are always passing threw the mesh! I fixed the problem by making the colliders very big, but that make it feel so clunky and unnatural when moving up to an object. As there feels like some invisible air between them both. It's also visible when hitting object off of it. I tried to fix the problem by setting up a second camera that only renders the characters weapons. This works so well and looks good. But then the problem is that I can't get the 2nd camera on the weapon only to render any animations!!!! Please help!