4 ways:

1) silver solder of 1100 degrees F
2) electric seam weld at least half the          circumference.
3)  4 evenly spaced electric tack welds points
4) traditional pinned and welded over

I can't find the original letterhead






DEPARTMENT OF THE TREASURY
Bureau of Alcohol, Tobacco and Firearms
Washington, D.C. 20226


Dear Mr. : xxxxx

This refers to your letter of March xxxxxxx in which you ask
about permanently attaching a muzzle device to various firearms.

A muzzle device, such as a muzzle brake or barrel extension, which
is attached to a barrel by means of welding or high temperature
silver solder having a melting point of at least 1,100 degrees
Fahrenheit, is considered to be part of the barrel for purposes of
measurement. A seam weld extending at least one-half the
circumference of the barrel or four equidistant tack welds around
the circumference of the barrel are adequate for this purpose.

A firearm having a muzzle brake, cap, or barrel extension
permanently attached by those same methods to cover the threads on
a barrel, would not be considered to have a threaded muzzle.
Please note, however, that any muzzle device or barrel extension
which functions as a flash suppressor or grenade launcher would
still constitute one of the qualifying features of a semiautomatic
assault weapon as that term is defined in 18 U.S.C. section
921(a)(30(B). Industrial adhesive products are not an acceptable
method for permanently attaching a muzzle device.

Mr.

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]

Edward M. Owen, Jr.
Chief, Firearms Technology Branch

No federal laws pertain to permenant magazines, thus BATF declined to answer the question and deferred it to state and local officials.

So you think the HPD would call the BATF about what constitutes a permanent mag and then they would get a similar response? Has no one gotten an answer on this matter before?

So you think the HPD would call the BATF about what constitutes a permanent mag and then they would get a similar response? Has no one gotten an answer on this matter before?

yes they told me so verbally

yes they told me so verbally

Is that good or bad? If the BATF is less strict than HPD it might not be that bad.