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

                           JUN 22 2000

                                                       903050:CHB
                                                       3311

Dear Mr. Bardwell:

This refers to your letter of May 30, 2000, in which you asked
about modifying a magazine.

As defined in section 921(a)(31) of Title 18, United States Code
(U.S.C.), the term large capacity ammunition feeding device - 

     (A) means a magazine, belt, drum, feed strip, or similar
     device manufactured after the date of enactment of the Violent
     Crime Control and Law Enforcement Act of 1994 [September 13,
     1994] that has a capacity of, or that can be readily restored
     or converted to accept, more than 10 rounds of ammunition; but

     (B) does not include an attached tubular device designed to
     accept, and capable of operating only with, .22 caliber
     rimfire ammunition.

It is generally unlawful for a person to transfer or possess a
large capacity ammunition feeding device as provided in 18 U.S.C.
section 922(w).

A 9mm 20 shot magazine manufactured prior to September 13, 1994,
would not be a large capacity ammunition feeding device as defined. 
You asked about altering such a magazine to accept 14 rounds of
10mm ammunition by modifying the feed lips and possibly the
follower.

                              - 2 -

Mr. Bardwell

The altered magazine would be a large capacity ammunition feeding
device.  The fact that the materials used to construct the 10mm
magazine were made prior to September 13, 994, would not mean that
the 10mm magazine was manufactured prior to that date.  A new 10mm
magazine with the capacity of accepting more than 10 rounds of
ammunition would have been manufactured and it would be subject to
the prohibition in section 922(w).

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


                        Sincerely yours,


                            [signed]
                      Curtis H.A. Bartlett
            Acting Chief, Firearms Technology Branch