Thanks for dragging me into this, since as an Australian, I must be staunchly against gun rights, and will therefore rush to your defence and explain that I only merited nullius because he articulated his point well even though I don't personally agree with it. Wrong! I'm pro-gun, and shoot occasionally myself, so I know something about it.
“Machine gun” means a weapon of any description by whatever name known, loaded or unloaded, from which more than five (5) shots or bullets may be rapidly, or automatically, or semi-automatically, discharged from a magazine, by a single function of the firing device
Bolded the relevant part of the definition. Since you clearly know nothing about firearms, I'll translate it for you. "Firing device" means the trigger, and "single function" means you press said trigger only once. Thus a machine gun is a gun which fires many bullets just be holding down the trigger, which corresponds to the layman's definition of a machine gun. (The military definition is a bit stricter, and adds the requirement that it be a "crew-served weapon" - at the very least you need an extra man to carry the tens of thousands of rounds of ammo needed to keep it firing continuously for more than a few minutes. Although military-issue rifles are capable of fully-automatic fire and thus are legally considered "machine guns" for purposes of civilian ownership, soldiers don't (and can't) carry enough ammo to usefully employ their rifle as a machine gun. Your idea that a thousand rounds of ammunition is excessive, which is already dubious, is an outright
joke in the context of machine guns.)
Possession or use of a machine gun for offensive or aggressive purpose is declared to be a crime punishable by imprisonment in the state penitentiary for a term of not less than ten (10) years.
But possession or use of a machine gun for sporting purposes ("sporting" merely being an archaic word for "fun") is A-OK. No, really, it is: while machine guns are subject to greater restrictions than other firearms, they're not actually illegal to own in the US.
Now we come to the nice weapon deals BayAreaCoins is offering here.
Which, of course, renders the above discussion completely moot, because
none of those are machine guns. Those are
all semi-automatic firearms (two pistols and three rifles) requiring a separate trigger pull for each shot.
As one can see all the guns are kept loaded (which is not good for the magazine springs, by the way):
Leaving aside the fact that in one of those pictures, two of the rifles don't even have magazines, those pictures say nothing about how those firearms are stored long-term when not in use. Briefly loading a firearm for purpose of taking a picture of it in loaded condition or even (gasp!) shooting it does not harm the magazines. (Even when a firearm needs to be stored fully loaded for defensive purposes, the magazines can be rotated regularly to mitigate spring fatigue.)
In conclusion, you clearly know nothing about guns or the laws regulating gun sales, and are therefore not entitled to an opinion on such matters until you educate yourself. (Your abuse of the trust system also indicates you have other issues, but that's another topic.)