It could utilize combustible light gas propellant technology, ETC, or both.

https://en.wikipedia.org/wiki/Combustion_light-gas_gun

https://en.wikipedia.org/wiki/Electrothermal-chemical_technology

The old Paris Gun, with its 81 mile range, fired projectiles that reached an altitude of over 130K feet.



I'm guessing that a 1000 mile range shot would need to go much higher than that, perhaps into space {which starts at roughly at the 330K foot mark}, and thus a ramjet wouldn't be able to function at such altitudes.

Watch when he hits a ball

No it's not a copy of anything because a 1000 mile range gun has never existed which to copy.

A purely ballistic, unpowered, trajectory that reached 1000 miles downrange would top out at over 300 miles above the earths surface. A ramjet powered shell wouldn't be a ballistic arc, it would cruise at a given altitude probably at or above 100,000 feet.

I can't see how ramjet technology alone would account for such a huge range increase over previous artillery systems.

Is the USA still making a rail gun for their Navy ships?

Trying I think. Let's look and see.

Whoops!

The U.S. Navy’s Railgun Is Nearly Dead in the Water


Let's hope they are working towards a kinder, gentler, and of course, a more gender neutral weapons system. Those big guns are sexist!

Just kidding of course.

Thank you Nixer. I remember it in Transformers.