According to the Guns vs Armor Webpage:
http://gva.freeweb.hu/weapons/german_guns1.html
25mm pen at 30 deg at 500m.
That works out to 29mm LOS Penetration. Considering the A9 cruiser has the following stats:
20mm Effective Hull Front
10mm Effective Hull Sides
10mm Effective Hull Rear
20mm Effective Turret Front
10mm Effective Turret Sides
10mm Effective Turret Rear
10mm Top Armor
it means the weapon can hole it at 500m.