The dishonorable discharge is based on a general court-martial conviction. This means the conviction is a felony, regardless of what the underlying offense may have been. The convicted felon is banned from possessing a firearm including Title II Firearms (a Silencer, SBR, SBS, AOW, or Machine Gun).
A person who is convicted of a crime that is punishable by imprisonment for more than one year ( including a dishonorable discharge) is prohibited from possessing a firearm. Under 18 U.S.C. 922(g), a felon who is found guilty of gun possession may serve up to 10 years in prison.
If you have been convicted of a felony or a dishonorable discharge, be careful of constructive possession. You could be guilty of being in possession of a firearm if your spouse or another family or household member has a firearm that you “could” access.
I don’t know if “bad conduct discharges” result in the same revocation of gun ownership rights as a “dishonorable discharge.”
His motives may or may not be discernible. However, it should be instructive to keep an eye on politicians in coming days and weeks to see who tries to use this incident to further their aims: to those politicians, guys like this are their heroes and footsoldiers.