But the round they made for it is a winner:

In 2015, SCO realized that the HVP, originally conceived as a specialized shell of the railgun, was just as effective when fired from a conventional powder cannons like the Army’s 105mm and 155mm M109A6 Paladin self-propelled howitzers and the Navy’s deck-mounted Mk 45 5-inch guns. A May 2016 report from the Center for Strategic and Budgetary Assessment found that large caliber guns could fire an HVP between 10 and 30 nautical miles at Mach 3, faster than conventional unguided rounds.

Just wait until it gets miniaturized into an AT rifle round. No armor will be safe.