Several readers pointed out the possibility of High Explosives being abandoned at National Guard Armories.
I don't want to dive down that rabbit hole because my ignorance is total. I could only speculate and would probably get important details wrong.
It does raise the question of likely actions by the National Guard if civil strife looked like it would go critical-mass.
My guess is that they would make a tactical retreat to major bases. In Michigan that would be Grayling in the middle of BF-Nowhere and Fort Custer which is mid-way between Detroit and Chicago.
Grayling is infinitely more defensible and Fort Custer is infinitely easier to support logistically.
The order of shipment would be fuzes, shells, then tubes.
Without fuzes, High Explosive is modeling clay. Fifteen fuzes take up the same space as one 105mm projectile so the least logistically demanding way to make ammo inaccessible to insurgents is to ship out or destroy the fuzes.
Without shells, tubes are very heavy telephone poles. One-hundred 105mm HE rounds weighs about as much as a 105mm howitzer.
A minimum amount could be kept together to ship with the tubes in case locals got ideas and barriers needed to be breached.
Any comments from the professionals will be much appreciated.