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

                              MAY 26 1995


                                                      E:CE:F:TE:GKD
                                                      3311.4

Dear Mr. :

This refers to your letter of April 1995, asking questions relative
to modifications of Heckler and Koch SP89 pistols and their
markings.

Your first request was to remove the metal plates at the rear of
the receiver, enabling a collapsible stock assembly to be mounted
on to the firearm when a registered machinegun sear was installed
in that particular firearm.

There are no provisions in the Federal firearms laws to prohibit
the removal of the metal plates referred to in your letter.  With
a registered machine gun sear installed in an SP89 pistol, the
owner could install a stock assembly to that firearm.  However, if
the machinegun sear were to be removed from that firearm, the stock
assembly would have to be removed as well and either the firearm
would have to be rendered incapable of accepting the stock assembly
or the stock assembly would have to be disposed of to prevent the
owner being in violation of the National Firearms Act (NFA) by
possessing an unregistered short barreled rifle.

With regard to your request to be able to remark a Heckler and Koch
SP89 pistol as an MP5K model, there are no provisions in the
Federal firearms laws to prohibit such a practice.  However, the
serial number must remain unaltered and not obliterated.

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


                           Sincerely yours,

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