A few thoughts
Yet then you move onto # of adults? Naughty. The correct baseline is the 115M households.
47% of 115M is ~ 54 M (which matches up with your other numbers).
Now...does it make sense that there are 200M+ guns?
Well, to begin with...200M / 54M means only 4 guns per family. You might think that's high, but that could mean a rifle, shotgun and say a pair of pistols.
And that's just the average. One friend I had who liked to hand-load his pistols owned 12, iirc.
At 6M new guns being manufactured in the US per year, that's less than half the number of new cars sold in the US every year. There are roughly 250M cars registered in the US. Cars last roughly 10 years. Do gun owners buy new guns every 5 years on average? I don't think so. I think the average person who buys a gun buys one and are done with it. One has to make a lot of inferences to say much more.
Actually, I'd give you a little more to chew on. Most guns last a lot longer than cars. There are a lot of Colt 45, etc. out there. There are guns that are older than 100 years. (Not many cars can make that claim)
(Hell, the M1911 was named for the year it came out....and it's 2013 now)
So, can I believe 200M to 300M guns? Yep.
Do I think the majority of Americans own guns? Nope. (I'd agree, it's probably closer to 20%)
And I do think most gun owners own more than one gun.
As for the suicide...I'll fully admit that owning a gun (or any weapon) increases the chance of being harmed by it (accidential shootings and the like).
And while I suspect that the facts are borne out regarding suicides...I'm not sure it's painting a complete picture either. The cases of suicide with guns that I can think of (3 off the top of my head), one...maybe two...occurred because the gun was available.
The third - she did use a gun. But she first tried to slit her wrists (incorrectly) and nearly chopped off her hand in the process.
I don't think restricting the ownership of guns would've stopped her in that case.
