Guns deaths vs Gun control

Source: my own calculations, which are here.
US States with one party in power for 4+ terms

I went looking for a chart of gun deaths vs gun control.  There are heaps which show gun deaths vs the number of guns, per US state.  But none -- that I could find -- that put gun deaths per state vs the strictness of gun laws in those states.  The reason I was looking is that the whole argument -- repeated every time there's a mass shooting in the US --  is whether gun control works or not.
So I made my own chart, as above.  The "deaths per 100,000 population" comes from Wikipedia.
The gun control comes from this site, which includes only those 26 states which have had one party in charge of that state for at least four election cycles, presumably on the rationale that it takes more than one term to set a pro/anti gun control policy in place.
[My poor Excel skills means I wasn't able to label all the dots (at least not easily) with the individual state name; but it doesn't really matter to the main point, which is the relationship between deaths and gun control].
I then did a correlation calculation which came to minus 0.78 (which I've converted to "78%" above).  That shows what you might expect as a gun control advocate: namely that the stricter the control, the fewer gun deaths.  In other words, a negative correlation. In this case a "very strong correlation".
Now, the anti-control folks will say "of course correlation is not causation".  Indeed that's correct.
But in this case, what could be the other factors that make the red states above have figures of gun deaths of up to seven times that of the blue states?
What is it? Demographics? Religiosity?  Distance from Washington DC?
Fact is, the logic behind the correlation also being causation is so commonsensical that the onus is on the anti-gun-control folks to come up with why that chart above is not showing any causation.
The "Brady score" comes from the Brady Campaign to prevent gun violence.   Jim Brady was with President Reagan over 30 years ago, when the assassination attempt was made on Reagan, and Brady was shot and paralysed. On the situation of gun control per state in the US, his Foundation has become the go-to source.
SUM:  just have a look at the cluster of Red States (Republican) in the top left!  This means simply this: those states all have very low gun control; and they all have average gun deaths way above the national average.  Up to seven times of the lowest of the Blue States (Democratic).