Consider that the ready access to explosives has been only restricted in the US for less than one lifetime. How many civil rights RKBA activists even try to get access to explosives and various tools containing them (grenades, mines, detcord, satchel charges, RPGs) less restricted? Now consider that non-government Japanese have been denied all arms for at least five hundred years, and you can see why few would bring up the topic in polite company.
And yet, this is a topic that has to be brought up. As the world-wide experience with modern warfare shows, civilians with only small arms can’t take on even light armor, dooming them to retreat after retreat until there’s no place to run. Just as the 1570s samurai learned that bows may be useful but cannot replace muskets, we should understand that even accurate rifles with a decent rate of fire cannot do the job of Claymores, RPGs and mortars. And US gun owners are as far behind the power curve as the Plains Indians were in the 1880s. Denied not only the more potent weapons but also the training and maintenance know-how, the Indians couldn’t have made much use of a Gatling even had they captured one, and American civilians by and large cannot use a mortar, a personnel carrier or even a Claymore safely and effectively.