Unless they are kicking the shell up out of the atmosphere, which I don’t think it is capable of, the range will be shorter, especially if they are relying on kinetics over explosives.
The story I saw in NBC Monday night showed the explosive power of a 20 pound warhead fired at Mach 7. The engineer gloated this could hit an object 2,000 miles away w a velocity of 5,400mph and proper elevation.
Just sayn
Using a trajectory calculator, if we neglect air resistance (which, I know, we can't, and it WILL be a big factor, but bear with me) a shell fired at a 45 degree angle at 7920 f/s (= 2414 m/s) would go 594 km, reaching a peak height of 148 km, which is above most of the atmosphere.
Yes, long range shots would put the projectiles in space, just not in orbit. That keeps the velocity quite high.