Examples from the Web for cupronickel
Our armor-piercing bullet was made with a cupronickel jacket for the sake of the gun barrel.
The tracer bullet consisted of a cupronickel shell, the nose of which contained a leaden core to balance the bullet properly.
On one side of the missile was a hole drilled through the cupronickel into one of the grooves of the serrated plug.
As soon as the cupronickel jacket strikes the armor plate it splits and the lead core flattens out and flies into fragments.