The Term “Mil-Spec” AR-15 refers to an AR that has parts (with the exceptions that I will list) that are manufactured to US Govt specifications with regard to metallurgy, dimensions, and tolerances for those M-16 variants that are acceptable for US government acceptance. For instance, the “Mil-Spec” upper receiver of a Military M-4/M4A1 carbine is identical to that of a “Mil-Spec” AR-15 receiver save for barrel length, so as to comply with the unconstitutional NFA of 1934. Even so, a few minutes with an armorer’s wrench would allow the military 14.5” carbine barrel to substitute for the 16” civilian one. Every other single part of the upper receiver, to include the bolt carrier group, front sight/gas block, gas tube, ejection port cover, handguards, and forward assist will all readily exchange.
The lower receiver has the exact same external dimensions, and either lower receiver will interchange and function (in semi-auto that is) with either platform by pushing out the two retaining pins. The only significant difference is a hole drilled for the auto sear pin, and a shelf machined into the lower receiver to inhibit the substitution of the NFA legal “civilian” fire control parts with the selective fire parts of the “military” rifle, which are the 5 following parts, the hammer, the disconnector/sear, the auto sear, the selector/safety lever, and the trigger.
When I was an infantry squad leader in Nam, I was constantly admonishing my squad mates to make discriminating use of the full auto position, because the M-16A1 rifle was really a semi-auto rifle capable of full auto to be used that way in a few circumstances like breaking contact in ambushes, the final stages of an assault, final protective line fire, and to gain initial fire superiority. Using it as a squad automatic weapon would invite overheating, and premature wear and breakage, as it was not designed for the purpose of sustained automatic fire. So the “Mil-Spec” civilian version of the M-16 platform is, for all practical purposes identical to the military version in the role for which it was principally intended to fulfill, along with near total parts interchangeability.
A militia has been defined by SCOTUS as a “body of citizens intended for military purposes.” If that is true, then the selective fire version of the M-16 family is PRECISELY the weapon suitable for that type of organization. We need to repeal the unconstitutional NFA, and restore the militia to the prominence of place that it once had prior to the adoption of the National Guard in 1903 with the passage of the Dicke Act.
The 2nd amendment was not intended to allow you to punch holes in paper targets and to shoot bunny rabbits. (even though it serves incidentally to allow for that too, along with any other lawful purpose) It serves to provide an additional bulwark that is “necessary to the security of a free state.”
The Kansas Constitution is even more explicit than that:
ยง 4. Individual right to bear arms; armies.
A person has the right to keep and bear arms for
the defense of self, family, home and state, for
lawful hunting and recreational use, and for any
other lawful purpose; but standing armies, in time
of peace, are dangerous to liberty, and shall not be
tolerated, and the military shall be in strict subordination to the civil power.
I can live quite well with that definition of my rights. Regards.