No, I am not worried about another Civil War. The circumstances for that type of thing just don’t exist in this country. Loud “noise” from the fringes can be deafening but their numbers are small in comparison to the overall population. Think about where you live and your neighbors. They struggle with everyday problems and challenges, go to work, vacation, raise their kids, etc. Are any of them thinking about participating in a civil war? Probably not! Now compound that by millions of people in hundreds of thousands of neighborhoods. If you study history, and I hope you do, you will find many periods of extreme trials and tribulations in this countries past. Of all of those, only one lead to a civil war and that war was a logical conclusion to the unfinished issues in the constitution and its great compromises that just could not be sustained over time (states rights, slavery, federalism).
As far as the purchase of ammunition by the government, that has largely been debunked and you can read about that around the web. The numbers were exaggerated and the time frame of the purchase was longer than stated (it is over many years). But even so, they have or will purchase a lot of ammo over the decade. A good portion gets used at the firing range by all of the various federal law enforcement officers (FBI, US Marshals, ATF, DEA, Customs, Prison Guards, Secret Service, and there are more). Yes, we could have a whole discussion about the sheer number of armed federal officers of all types but that is for another time.