That's The Shadow, famous old pulp-fiction crime fighter. One of the baddest badasses to ever blast bad guys with bullets. Now, how many guns does the Shadow use?
Two. Why? Because he only has two hands!
Bearing that example in mind, shouldn't the reasonable maximum number of guns any individual owns be... two?
I'll shoot down that conclusion myself. Because handguns and pistols have their uses, but they're pretty much crap for hunting purposes. (Yes, there are people who hunt using handguns. There are also people who like to be tied up while having sex.)
For hunting, you need a rifle. You need both hands to use a rifle. So you only need one rifle. That means the maximum reasonable number of firearms any individual needs is three, right?
Ehh, not quite. There are some types of game (ducks and doves, for example) where you're trying to hit a small, fast-moving target at a considerable distance. For that, you need either very good aim and a lot of time and a lot of rifle ammo, or you need... a shotgun.
So now the count stands at two handguns, one rifle, and one shotgun.
And I think that pretty much covers all the reasonable bases for owning firearms. More than four seems excessive to me.
But, Bruce, what about collectors who buy guns for their aesthetic and artistic value?
Sure, as long as they only keep enough ammunition on hand for two handguns, one rifle, and one shotgun. Have you considered collecting hood ornaments, or Snowflake Babies, instead?
But, Bruce, government tyranny, anarchy, Scary Brown People...!!!
There are medications to help you cope with those thoughts. Anyone who feels a need to stockpile huge numbers of firearms, ammunition, etc., doesn't meet my definition of "reasonable".
So, in short, you only have two hands. You can only use one rifle, or one shotgun, or in rare instances two handguns, at a time. Is there really a good reason to own more than that?
Well, I suppose with modern technology and some engineering skills, you could rig something up to let you use other bodily appendages to fire weapons. But the you run the risk of turning yourself into this guy:
On the list of Lamest Super-Villains Ever, this guy is near the top.