A military application of electromagnetic force is the rail gun.
A rail gun is like a regular gun in the sense that it fires a projectile out of a barrel, but it has some major differences.
A regular gunpowder gun uses a projectile with a firing pin, which is hit by the gun, pressurizing gunpowder, resulting in an explosion which propels the projectile forward. This is a bit inefficient however, because a lot of recoil occurs in the gun because of conservation of momentum, and a lot of excess heat is produced.
The rail gun propels the projectile differently. Instead of using gunpowder to propel the projectile forward, the gun uses electromagnets along the barrel to accelerate the projectile to high speeds. this results in a less sudden recoil and a more efficient way to shoot a projectile, and as the technology improves, rail guns will eventually replace large guns for military use.