Been covered. Was a bad conduct discharge. Doesn't carry immediate weapons ban. And even though he was court martialed for domestic violence which would bar ownership if a civilian charge and served a year, apparently it doesn't translate out of the military with the discharge to an ownership ban.
Seems like a good time to amend either military code of justice to move assault on women and children to dishonorable. Or amend the 68 gun law to include a more wide range of court martial convictions to not able to buy a gun.