In this world, the law enforcers and Military uses a new, multipurpose weapon which is basically a:
Packed into a single weapon. However, when designing the weapon, it's important to determine the parts that can be interchangeable in these two systems, so the question is:
What can be made into the shared parts of a free electron laser and a railgun, with nanotechnology?
- Reversible, quick changes are allowed in the parts.
This question is tagged science-based because both of these systems exist in real life.