Errr, this might be a stupid question but why would anyone want to have such a weapon?
What do you mean by "such a weapon"? It is just a semiautomatic firearm of the kind used to hunt with for nearly 100 years.
Where does this stop?
What are you talking about? Modern military small arms are generally less powerful than their civilian counterparts. Except for the full auto weapons, which aren't very popular among civilian gun owners anyway.
Should we encourage selling outdated Army tanks to the general public?
YOU brought that up, no one else did. No one is seriously proposing to do that, either.
And please . . . don't say it's for hunting.
And how many people do you know who want to buy a tank for hunting?