Found this at:
http://www-2.cs.cmu.edu/afs/cs/user/wbardwel/public/nfalist/atf_letter41.txt
21032
June 11, 1970
Assistant Regional Commissioner (ATF)
Southwest Region
Alcohol, Tobacco and Firearms Division
National Office CP:AT:EO:[]
Okla, LI 3134 - [ ] - Removal of Firearm from machine gun
SWR SI 998 [ ] category
This refers to your Information Transmittal of February 16,
1969, with attachments, requesting a ruling concerning the status
under the National Firearms Act of a U.S. Carbine, caliber .30 M1,
serial number [ ], converted to an M2 capable of full automatic
fire and now restored to its original condition as an M1 capable of
only semiautomatic fire.
The U.S. Carbine, caliber .30M1 is a semiautomatic rifle and
is the basic model from which the M1A1, M2 and M3 models were
developed. Therefore, the U.S. Carbine, caliber .30 M1 did not
evolve as a machine gun. Accordingly, an M1 Carbine, as marked,
converted from semiautomatic fire to full automatic fire, may be
removed from the classification of a machine gun by the removal and
destruction of the conversion parts. We believe this position is
consistent with the provision for the removal of a short-barreled
shotgun from the purview of the Act by replacement of the short
barrel with one over 18 inches and for the removal from the purview
of the Act of a semiautomatic pistol which was modified to fire
full automatic and which is returned to semiautomatic fire only, by
replacement of the modified part or parts. We reaffirm our
position that a weapon originally designed as a machine gun remains
a machine gun and may not be removed from the purview of the Act.
In accordance with the above, the information given by [ ] of
my staff to [ ] is correct and [ ] may be advised that in view
of the fact that he has abandoned the full automatic parts from his
carbine to the [ ] branch office, we have removed his firearm
from the National Firearms Registration and Transfer Record.
[ ] Director
Attachments
6/10/70
