You're absolutely right, the government can screw off. I'm cutting down all my shotgun barrels today when I get home. I've had enough of their meddlin'. While I'm at it... can somebody tell me why can't I have sex with a 13yr old girl as long as it's "the way I figure it" in my own home?
DISCLAIMER: The above paragraph is intended to be sarcastic.
DISCLAIMER TO THE DISCLAIMER: The above paragraph may or may not be sarcastic depending on what state you live in.
In all seriousness, rifle and shotgun barrels are regulated by law. You can get a legal short-barreled shotgun just like you can for a short-barreled rifle, a suppressor or fully automatic rifle. If you want to cut your shotgun down to 14", find a Class-2 dealer and do it legally. So yes, your statement of "the way I figure it" is accurate, but it will cost you $200 and a hacksaw blade.
Or you could do it even easier and buy one new from a dealer (Class-2 or 3)... this is just the first one I found, not my recommendation, only listed for reference:
Oh yeah... don't forget a holster: