In CT I read the law as a semi auto surplus military gun not having all three evil things on one rifle. I/we can't have the detachable mag,,, the muzzle flashhider and a bayonet lug on the same rifle. The rifle can have two of thye three but not all three items on one rifle.
My point is that I can have the detatchable mag and the flash hider on one gun but i need to cut off the bayonet lug. Of course my m14 has no bayonet lug (i purchased it on ebay all cut)