How broad is the right if the second amendment does create a individual right??

Based on the Supreme Court’s findings in United States vs. Miller (1939), DC vs. Heller (2008) and McDonald v. Chicago (2010), discuss the following. If the Second Amendment does create an individual right, how broad is the right? Does it include the right to possess arms that would be useful to a militia today–hand grenades, rocket launchers, etc.? Or does it create only a right to possess arms that would have been used by a militia in 1791–muskets? Or is the right answer somewhere between these extremes?