I was hoping they would send assassians after me for killing Ceaser and his entire camp. But somehow it got back to Neutral status from Vilified. I wanted to test out my new guns and ammo on their corpses. I've been wearing NCR Ranger Combat Armor with boone's beret and authority glasses. I just got shunned by them too for helping the Kings in Gi Blues. I need more target practice anyways. But I was just curious if anyone else has seen the random faction status changes.

Once you lower your reputation, you can't remove it except for the plot events with NCR and the Legion. The reputation change occurs because NCR Ranger Combat Armor is treated as a disguise and thus will change your reputation with the main factions to neutral.

So what you are saying is that I need to kill a lot more of them, again? lol Time to dust off that Brush Gun.

No, any reputation changes you get while in a disguise WILL NOT APPLY AT ALL since there are no reputation bars in the disguises. You're stuck with the reputation you had before the disguise.