Pretty much a custom proposition. Do a google search on custom shotgun makers and start making phone calls.
Custom build nowadays
Tough question, the Remington model 550 is a .22 rifle not a 12 gauge shotgun.
You can purchase parts for a Ranger model 30 16 gauge shotgun at these locations. Gunbroker, Topgunsupply, Budsgunshop, Gunpartshop and Midwayusa.
mite check guage 20 or 28 guage
no serial noreg
Yes. The Mossberg 500A1 is a .12 gauge shotgun.
A bolt action shotgun in 12 gauge.
Yes, a 12 gauge shotgun is considered a firearm.
There is no such shotgun gauge.
Not currently produced. Start with your local gun shop.
It is a shotgun with 20 gauges.