FNC HOST GUNS and registered SEARS

[mike todd]

I have an FNC rifle with a registered sear, the form 4 shows the serial no and manufacturer of the sear in the main description. on the line below for other information, the guns serial no and model (FNC) are listed.  when I bought it as part of a group, I did not pay too much attention to the gun but did look at the forms close. it was said at the time that the registered sear could be moved from gun to gun "no problem". because I have others ,  it was close to a year before I got around to shooting it and while cleaning it afterwards I looked closely at the sear and what was done to the gun to install it. obviously there is a hole drilled for the pivot pin that hold the sear. also the receiver was milled to create the space it go's in.  the way I see it, with the alterations the gun itself is now a " machine gun " by itself. but understand its law full with the sear installed. WHAT IF ITS REMOVED AND IN ANOTHER GUN? I have several semi's as back ups for the sear. if I do the same alterations to them so I can move the sear around am I not creating " machine guns " and violating the act? most of my stuff is WWII or before and other than the HK sears which are easy I'm not up to date with the process of moving sears around.  I thought that altering the receiver to take auto parts created a machine gun. help me get it RIGHT GUY's PLEASE    cheers mike