Being a gunsmith I'm always looking for punches. Concave ends, roll pin, straight.
Gotta be strong AND tough.
Gotta have short strong starters and longer to drive pins out.
Punch body that lets one replace the punch itself w/o having to replace the whole thing when they break/bend/ give out.

Don't know about AKs so much. Pretty simple. AR tools are so reasonable & readily available.