If someone can please answer this question it would be greatly appreciated, I am purchasing a upper with a 16 inch barrell, my question is, the muzzle break is not welded on permanant, with the muzzle break off it will measure 16 inches, can someone please tell me if this is legal here in New York? Thank you, a response asap would be appreciated.

It is not illegal seperated from a post ban lower , if placed on a post ban lower it will be illegal.  However, that depends on the "type" of muzzle break, for example an A2 birdcage would be illegal pinned/soldered or not.  My recommendation is if a muzzle break and all of the supposed nasty stuff is what you want get a pre-ban and save yourself the heartache.  If you call the ATF in Albany, they will help you they are pretty nice guys and are willing to give you guidance.  The interesting thing is most police agencys in New York have no clue what is preban and what isnt.  Sell the post ban save up and get a preban, its just easier.

As far as I know a BATF aproved muzle break is perfectly fine.  Flash suppressers and compensaters are not ok, except on preban lowers.  A break can be attached using set screws which wouldn't make it permament.  As long as the barrel is 16 inches without the break and isn't threaded you should be fine.