The instant you give government the power to limit the right to bear arms in any way, they will eventually limit you to zero.
For a very long time, there were no real regulations on firearms possession in the US. Then, the NFA happened to handle "criminals". That act made the government into criminals.
I do not "trust" a marine with a gun, if he believes he is in service to a government. Nor should you.
If the people do not have access to equivalent arms as the infantry, they will eventually be attacked. It's already starting. You need to decide of a few hundred innocent lives are worth the trade of a few hundred million, and slavery to the State, in the long run.