Because 1. that includes tens of thousands of collectors too.....
32% of US households have firearms. The 300 mio registered guns also doesn't mean that they are all still in legal possession. Many of then are in the hands of criminals.
But lets even neglect that...... Let's count totally idealized to showcase...
32% of 315 mio. is 100.8 mio. 100.8 mio people have a total of 300 mio legally registered firearms. Which makes it roughly 3 weapons per household.
That's idealized, extremely even, since household sizes vary. And there are not 315 mio households. But it gets close to the reality, as far as a ballpark number can go.
Now in case of any tyranny you imply that all those 32% households would automatically be part of the resistance? I highly doubt that.
I am sure it's safe to say that not even 50% of said households would join any resistance.
N-7 is right on the money there.
If the army doesn't back any tyrant, the tyranny would be over before it even starts.
If the army does support the tyrant, then there's no chance in hell to defeat it. Especially not THAT army. The USA prides itself to sport the most advanced and highest trained army anywhere in the world. And you believe that a bunch of farmers with pitchforks (not much more are those weapons in the hands of untrained civilians) are capable to defeat that army?
If you really believe that, make sure to send your family away before you start the rebellion. Because they will suffer, and they will suffer bad.
Remember, you want to take on a tyrant. Tyrants don't hesitate to kill for no reason at all.
And where exactly would you want to fight? it's not a guerrilla war. The army is at home here. They are on their own turf too.
In the resident areas? Hiding behind and inside houses? Those cardboard boxes, called a house give almost zero cover. They are built with 2x4's, plywood and drywall sheets. They blow up in a second.