Deaprtment of the Treasury
Bureau Of Alcohol, Tobacco and Firearms
Washington D.C. 20226

April 7, 1995

E:CE:F:TE:GKD
3311.4

Mr. XXX
address
address

Dear Mr. XXX:

This refers to your letter of February 10, 1995, in which you ask 
whether the installation of a registered AR15 drop-in auto sear
into an AR15 type rifle manufactured after the effective date
of Title 18 United States Code (U.S.C.), Chapter 44, Section
922(v)(1) would remove the AR15 rifle from the provisions of 
Section 922(v)(1).

Installation of a registered AR15 drop-in auto sear, along with
the necessary M16 trigger, hammer, disconnector, selector and bolt 
carrier, into a semiautomatic AR15 rifle would remove the subject rifle
drom the provisions of Section 922(v)(1), as the firearm would
then be a machinegun and not a semiautomatic rifle.  At this time, 
features such as a collapsible stock, separate pistol grip, and
threaded muzzle with a flash hider could be installed.  Please
note that the National Firearms Act Branch of the Bureau of Alcohol,
Tobacco and Firearms must be notified into which firearm you intend
to install the drop-in auto sear and the necessary M16 fire control
components.

Should you later decide to remove the auto sear from the AR15 rifle,
the M16 parts installed must be replaced by semiautomatic configuration
AR15 type parts, as the presence of M16 fire control compnenents
in an AR15 can cause the rifle to operate as a machinegun.  Further, a 
semiautomatic AR15 rifle would have to conform to the provisions of 
Section 922(v)(1).  As a semiautomatic rifle that accepts a detachable
magazine, the firearm could have only one of the following features:

- a folding or telescoping stock;

- a pistol grip that protrudes conspicuously beneath the action of
the weapon;

- a bayonet mount;

- a flash suppressor or threaded barrel designed to accomodate
a flash suppressor;

- a greande launcher.

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

Sincerely yours,

[signed]

Edward M. Owen, Jr.
Chief Firearms Technology Branch