300? Very little. I would assume you'd be instantly arrested, lose your 2 amendment rights and get thrown in prison for twice as long as some gangbanger who shot a whole family of Griswolds while committing a carjacking.
3000? Eh, maybe some folks would take notice, talk about you enough to avoid prison and arrest possibly.
300,000? Now the powers that be have an issue. They cannot allow this continue, but at the same time t forcibly arrest and contain that many people would certainly touch off at least some skirmishing.
3,000,000? The system would be forced to stand down.
I'm sure you won't agree, but I am firmly convinced that the ONLY reason the fedgov has not gone over the top, bat$#@! authoritarian, YET is because of the fact that roughly one third of the adult population is armed to the $#@!ing teeth, with hundreds of millions of guns and billions of rounds of ammunition.
I'm sure they are also aware, as am I, that not one in 100,000 of those people would ever find the stones to stand and use them as needed and appropriate.
99 percent sure of that.
But then there's that one percent chance...