So, I find it strange that there are tons of NIB Mac's out there.... who were these made for and why are so many still NIB.... good site(sub guns)... thanks...
There's 20 or 30 thousand of them. They're the most common transferable, by far. IIRC the reason there's so many is that the idea was to sell them overseas to private buyers but the passage of ITAR in the late 70's made it illegal to export machine guns from the US for sale to non-approved buyers (i.e. anyone other than friendly foreign governments).
And if you want a machine gun under $10k, the best gun by far will be a full-auto AR15 conversion. They're on the higher end of the price range ($8k and up) but for the money they're the best option because:
1. You can effectively convert them to a different gun by swapping an upper. I've used my M16 with mag-fed 5.56mm, belt-fed 5.56mm, 9mm, 7.62x39 and mag-fed .22LR uppers and am probably going to get a belt-fed .22LR upper soon. No other transferrable machine gun is nearly as versatile. The closest would be an HK sear, but even then you can't get a .22LR host (that I know of, correct me if I'm wrong here.)
2. M16 parts are cheap. Compared to the aforementioned HK sear, changing calibers means you have to get a whole new host gun instead of a different upper, and the host guns are generally much more expensive too. Also, working on an HK generally requires a gunsmith, whereas doing something like rebarreling an M16 upper can easily be done by someone in their garage.
3. M16 parts are plentiful and have multiple manufacturers. For example, if you burn out a barrel on an AC556 you're stuck with whatever Ruger wants to sell you. If you burn out a barrel on an FNC you better hope you can find one of the few aftermarket Green Mountain barrels that became available in the last year, otherwise you're SOL. Break something else? Better buy a second FNC to use as a parts gun.