system
Given the following post, respond as if you're commenting on Reddit:
human
Would electrically or magnetically propelled projectiles cause recoil?

I'm writing a science fiction story, so I'm looking for some accuracy on this point.

So, rail guns and similar weapons use alternate means to propel their projectiles, such as magnetism.  So without using combustion, would there be no recoil exhibited on the gun or is recoil caused by more than just the gunpowder's combustion?
gpt
There would still be a recoil.  The projectile is being accelerated by some means, being is compressed gas from gun powder, electric charge separation, or anti-aligned magnetic moments.  Regardless of the method of propulsion, Newton's laws still hold.  

For a magnetic rail gun, the force that the rail gun applies on the projectile is equal in magnitude to the force the projectile pushes back against the rail gun.  So the gun will experience some movement when fired.  However, if the projectile is being accelerated by a magnetic pulse that travels down the length of the barrel, the force can be much smaller since it is being applied over a larger distance compared to the explosion of gun powder.  

This could be designed to be a much more smooth action than a powder weapon (a long slope of force instead of a spike).  In other words, for the purpose of your fiction story, there is still recoil, but it can be greatly diminished compared to a powder weapon.