That’s great.
Now, how do you put the projectile on target at 100 to 200 miles? Is your target moving or stationary? How do you guide it in real time? These are not small problems and we don’t yet know whether the rail gun on the JHSV has the power and cooling ability to make the EMRG work.
A demonstration of the EMRG under ideal conditions is one thing, getting it to work is another thing.
Fire several. A guided missile costs hundreds of thousands or millions of dollars each. A block of iron is a bit cheaper. You could probably throw iron blocks for a year for the cost of a cruise missile.