Why not just buy the $190.00 .22lr conversion kit for your 5.56 AR15 from CDNN?
You DO have a 5.56 carbine, right? If not, priorities are skewed..
"Who are the militia? Are they not ourselves. ... Congress have no power to disarm the militia. Their swords, and every other terrible instrument of the soldier, are the birth-right of an American" Tench Coxe 1788.