There are ways to change how the hashing algorithm adds entries to HW but it does not always work.
1) Could try to change the hash algorithm to CRC 16 from CRC 32 (which is default).
- configure forwarding hash-algorithm crc16 (reboot needed)
2) Change the hardware from C series to XL blades, as the XL blades use the TCAM table and not the hash table.
3) Need to move these MAC addresses which are not added to the Hardware Table away from the switch, or segregate the network to aggregation switches, and break the l2 boundaries to the aggregation switches.