Seems about right. https://en.wikipedia.org/wiki/Project_HARP https://en.wikipedia.org/wiki/Project_HARP (1966) got 2100m/s from a ground-based cannon: this got

Seems about right. https://en.wikipedia.org/wiki/Project_HARP https://en.wikipedia.org/wiki/Project_HARP (1966) got 2100m/s from a ground-based cannon: this got the projectile to 179km.