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

                           OCT -1 1998          F:FPD:FTB:GKD
                                                3311


Dear Mr. :

This refers to your letter of July 21, 1998, requesting
information on permissible modifications to Uzi firearms that
have been converted to machineguns and registered in the National
Firearms Registration and Transfer Record (NFRTR).  Your
questions will be answered in the order received in the letter.

1.    If an Uzi type firearm was registered as a machinegun and
      the conversion involved making a bolt to fit in the
      semiautomatic receiver, with no modifications to the
      receiver, can the receiver be legally modified now, so that
      the standard factory Uzi machinegun parts may be used?  What
      if the bolt made to fit the semiautomatic type receiver is
      destroyed as part of modifying the receiver to accept a
      standard machinegun bolt?

Destruction of the registered Uzi conversion bolt would not allow
modifications to the semiautomatic Uzi receiver to allow it to
accept an Uzi machinegun type bolt.  The alterations to the
receiver necessary to accomplish installation of an Uzi
machinegun bolt would result in the making of a machinegun, as
the altered receiver would be a machinegun configuration frame or
receiver.  It is unlawful for anyone to make a machinegun except
as provided in 18 U.S.C. section 922(o).

2.    If an Uzi semiautomatic carbine is converted into a
      machinegun with a slotted conversion bolt which is itself
      registered as a machinegun, may other remaining features of
      the semiautomatic firearm be removed?  In particular;

      (a)  May the barrel retaining ring, an integral part of the
           feed ramp in the semiautomatic Uzi carbine, be removed?

                                 - 2 -

Mr.

      (b)  May the barrel trunnion be bored out so that the gun
           will accept unmodified Uzi machinegun barrels?

      (c)  May the sear openings in the bottom of the receiver be
           enlarged up to permit the use of a full automatic style
           sear?

      (d)  May the model name (only) of the semiautomatic carbine
           marked on the left side of the receiver be removed and
           replaced with a more appropriate marking for an Uzi
           machinegun?

The alterations described above as (a), (b), and (c), done to a
semiautomatic configuration Uzi carbine receiver, would not be
prohibited, as they do not convert the semiautomatic receiver
into the configuration of a machinegun frame or receiver.

With reference to altering the markings, as described in (d),
this would be permissible provided that no markings are removed,
altered or obliterated that would result in a violation of Title
18 United States Code (U.S.C.), Chapter 44, section 922(k) or
Title 26 U.S.C., Chapter 53, section 5861(g).

We trust that the foregoing has been responsive to your inquiry. 
If we can be of further assistance, please contact us.

                           Sincerely, yours,

                               [signed]
                          Edward M. Owen, Jr.
                   Chief, Firearms Technology Branch