Once Boston was occupied & the MA Militia activated, gunpowder was key, not arms. They had plenty of crappy muskets (not enough bayonets) but not much powder
And Pitcairn didn't say "turn over your weapons." He said "disperse, ye rebels"
1) No such thing as a Constitutional or Federal militia; that is enumerated to the States, where;
2) The unorganized militia falls under the purview of that State's Adjutant General & can only be activated under official auspices.