Be very careful what you wish for. As the oral arguments went, “military use only” could well end up being replaced by “civilian use only” which would clearly gut the primary intent of the 2d.
If you have any doubts, search the transcript for the phrase "common-use". You'll find it being uttered more than once by the likes of Scalia and Roberts in the context of commonly used civilian arms being protected while Our Hero Gura was throwing machine guns under the bus. .50 cal single shot rifles and "bayonet ready" EBRs could easily go the way of post-86 machine guns with that line of thinking.
The conservative members of the Court are going to realize that any decision will be more meaningful if the majority is greater. If Ginsberg can have the wool pulled over her eyes long enough, she just might vote for individual right with strict scrutiny, believing that the argument that machine guns are not in "common use" will prevent their ever again being legal to manufacture for civilian use.
Only during some later case need the fact come up that the NFA 34 was passed because machine guns were too common and were being used by gangsters to protect their turf and by bank robbers shooting up banks. It will then be too late to review Heller, but the new case will benefit from the obvious logic that the lack of "common use" cannot simply be a result of unConstitutional prohibition.