12 gauge home defense/tatical shotgun

[david86440]

Its true. You can do whatever you want to the stock's dimensons, just not the barrel's. 6 position AR-style, or a wood saw and a rubber recoil pad, whatever works.
FQ13

Not necessarily true everywhere FQ13:

A short-barreled shotgun means a firearm designed or redesigned to fire a fixed shotgun shell that
has a barrel or barrels of less than 18 inches in length or an overall length of less than 26 inches;

[WatchManUSA]

According to my training on the 4473 form a shotgun installed with only a pistol grip is no longer classified as a shotgun.  The 4473 must show it as defined as "Other.". If the owner of a shotgun takes off the stock and installs a pistol grip the gun does not need to be reclassified (at least in MN).