Can I get collision more precise?

This is what I get if I use convex decomposition. Is there a way to use the actual mesh as a collision?

If you need more accurate collision the best solution would be to use a 3d modeling program and make your own collision hulls with UCX tag then import.

Secondly you could use per poly collision that uses the mesh as the collision bounds by changing the settings in the details panel of the Static Mesh Editor > Static mesh Settings > Collision Complexity > Use Complex Collision as Simple. This will use more processing than the latter.

Lastly, you can use the simple box collision types in the Static Mesh Editor > Collision > add Box Simplified Collision. You can then scale, rotate, and move these into the position you would like.

Using Convex Collision is not always the best option for more complex geometry. It will give an approximation that is better when using more hulls and hull verts, but it will never be 100% accurate to every mesh there is. In 4.8 this will be improved with a new algorithm, but it will not be good enough to work for very complex meshes. Custom collision geometry is always the best in this case.

You can read more about collision here in our documentation: FBX Static Mesh Pipeline in Unreal Engine | Unreal Engine 5.1 Documentation

I hope this helps.

Thank you, very helpful! +1