Abstract: Steady-field coilgun methods and devices based on a steady-field coil(s). The fundamental operational basis is to leave the current running in the solenoid/coil during the operation of the gun or other projectile launcher, where the field must be built up only once-initially, when turning the gun or launcher on. Then firing involves loading a bullet or other projectile in the barrel and releasing it to be accelerated by the established magnetic field. To fire again, the system loads the next bullet into the barrel and releases it again to be accelerated by the same steady magnetic field. To stop the firing, simply prevent the next bullet from loading, or load it but do not release it in the barrel. To turn off the system, simply disconnect the DC voltage driving the current in the solenoid(s)/coil(s).