From: Tim

>> The time when orientation ceases to matter is when the crater depth
>> (from explosive effects) exceeds the penetration depth.
>
> That condition definitely holds at these speeds.

Not convinced it applies at velocities as low as 10 km/sec. If we consider a 1 kg steel projectile with a length of 25cm an aspect ratio of 10, we'd expect it to penetrate about 25cm into a steel barrier, and I don't think a 50 MJ explosion will produce a 25cm depth crater in steel. A 20cm bonded SD dart hitting bonded SD would penetrate about 20cm, and almost certainly won't produce a 20cm depth crater.