First of all, no matter the rationale provided as an example of why this inalienable right was enumerated, the sole operative portion of this Amendment is "the right of the people to keep and bear arms shall not be infringed."
There are no qualifiers placed on the word "arms," so that term is open-ended. Given the rationale provided in the beginning of the Amendment, the term "arms" was obviously intended to mean armaments necessary to successfully win a war, which means the inclusion of current, military-grade weapons.
"... being necessary to the security of a free state ..." is an interesting statement in that it could mean the state, as in the United States of America or as in the State of New Hampshire. To me, I believe the intent was "either or." So, if New Hampshire was threatened by a foreign power OR the federal government of the United States of America, the arms-bearing citizens of New Hampshire should have the wherewithal to fight, if deemed necessary.
The Amendment does not identify the source of any existential threat to the freedom of the "state," which by implication embodies the freedom of the "people," so this is open-ended to all comers - whether they be foreign or domestic tyrants who seek to put an end to The Constitution of the United States and the inalienable rights of individual freedom it enumerates.
So, IMHO ... yes, the Second Amendment is still very much "necessary to the security of a free state" because our well-armed citizenry is still an additional deterrent to foreign powers who might get by our federal troops and to treasonous Americans who might try to co-opt the federal government for their own nefarious reasons.