As long as you don't violate any federal laws or the hunting regulations for your area.
The legal minimum length of a non-rifled gun barrel in the united states is 7 inches.
no
Laws restricting sawed-offs are federal, though there's nothing illegal about shortening the barrel of a shotgun as long as the final product is at least 18 inches.
18
18
18"
18.5 inches
YES. I GUESS.
Yes
That would depend on the make and model of the shotgun in question,and the length of the barrel/barrels that came with the shotgun.
is it legal to own a double barrel shotgun in the state of OREGON