DEPARTMENT OF THE TREASURY
             BUREAU OF ALCOHOL, TOBACCO AND FIREARMS
                      WASHINGTON, DC 20226

                         MAR 25 1999                   903050:CHB
                                                       3311


Dear Mr. :

This refers to your letter in which you asked about possession of
spare M-16 machinegun parts by a person who possesses a registered
M-16 and a semiautomatic AR-15 rifle.

Any weapon which shoots automatically more than one shot, without
manual reloading, by a single function of the trigger meets the
definition of a machinegun in section 5845(b) of the National
Firearms Act (NFA).  An AR-15 rifle, which is assembled with
certain M-16 machinegun fire control components, and which is
capable of shooting automatically is a machinegun as defined.

The definition of machinegun in section 5845(b) also includes any
combination of parts from which a machinegun can be assembled if
such parts are in the possession or under the control of a person.
Thus, an AR-15 rifle possessed with separate M-16 machinegun
components can meet the definition of a machinegun, if the rifle
shoots automatically when the components are installed.

The fact that a person lawfully possesses a registered NFA firearm
does not grant authorization to possess additional non-registered
firearms.  A person who possesses a registered M-16 machinegun and
a semiautomatic AR-15 rifle and a separate quantity of M-16
machinegun components could be in possession of two machineguns.

                              - 2 -

Mr. 

We would advise any person who possesses an AR-15 rifle not to
possess M-16 fire control component.  If a person possessed only
the M-16 machinegun and spare M-16 fire control components for that
machinegun, the person would possess only one machinegun.

We trust that the foregoing has been responsive to your inquiry. 
If you have further questions concerning this matter, please
contact us.

                        Sincerely yours,


                       Edward M. Owen, Jr.
                Chief, Firearms Technology Branch