Unconstitutional laws are not laws.
From what I read on the internet, which I read can never be wrong or lie, says that no matter how much the barrel tapers externally, the bore is not. Any taper internally would affect pressure retention and create blow by. Make a cool suppressor that allows for interchangeable chokes ???
You are absolutely correct Rodburner. It wasn't tapered internally. If it was, not enough to make a meaningful difference.
There are some shotgun suppressors out there. I have an acquintance in New Zealand that made a heckuva suppressor by drilling a ton of holes in a 410 barrel and covering it up with an outer tube and filling the outer tube with a bunch of boot lace eyelets. It worked surprisingly well.