"By thus circumscribing the plan, it will be possible to have an excellent body of well-trained militia, ready to take the field whenever the defense of the State shall require it. This will not only lessen the call for military establishments, but if circumstances should at any time oblige the government to form an army of any magnitude that army can never be formidable to the liberties of the people while there is a large body of citizens, little, if at all, inferior to them in discipline and the use of arms, who stand ready to defend their own rights and those of their fellow-citizens. This appears to me the only substitute that can be devised for a standing army, and the best possible security against it, if it should exist.''
-Alexander Hamilton - Federalist #29
Any questions about the meaning of the 2nd Amendment have been answered quite clearly by our founders time and time again. All it takes to clear up ambiguity is to read what they wrote 200+ years ago.