WTK can I put a butt stock on this pistol

[suum cuique]

Originally Posted by MFC

Andy,
The BATF considers it a short barreled rifle. All rifles with a barrel shorter than 16" long are illegal (unless exempt). The reason the Artillery, navy , and carbines are exempt from the law, is because they are so collectable/valuable, that they would not likely be used in a crime.

Thanks.
BTW, is the military use of butt stocks documented with navy or regular 4 inch barreled Lugers? Does some photos exist?