This isn't rocket science. If the founders hadn't meant "well regulated," they wouldn't have said it, now would they?
You're maintaining that owning a gun is a liberty to which the founders referred. How about other liberties? Child sex? Revenge killings? It's a slippery slope.
Now while we know this nation isn't Christian as such, Christians are commanded to keep all laws unless they cause sin in itself. Not being able to purchase a bazooka gun is not a sin, so we should have no problem with it.
The government already regulates guns. Now it's just a question of how much.