You can get an inexpensive brass gauge that fits on a keychain from Connecticut Shotgun that essentially measures the muzzle diameter, but the result often doesn’t correspond to results observed on a pattern board since choke depends on constriction from bore diameter. Bore diameter can vary on these classic doubles.
Hunter Arms didn't mark chokes on their guns. If you ordered one they would bore them to your choice. Get somebody with a bore and choke gauge to measure for sure. But that only tells you what the constriction is. Shooting patterns at 40 yards and counting holes inside a 30" circle and figuring % tells you the choke. If 70%+ is full choke. 40% is cylinder. Is it a Fulton, Fulton Special, or Hunter Special ? They are all well made mid-grade guns and many times under valued.
I hunted with a 16 ga Fulton for years and it gave me excellent service. This was L C Smiths attempt to compete with the entry level guns from Parker and Fox. Notice that the gun is NOT marked L C Smith anywhere as they didn't want it compared with their sidelock doubles.
Jim
Fulton was building good doubles before they were assorted by lc smith,
They even sold some as hardware store guns
I have a 100 yr old + sears ranger 16 Guage that was a premium model with good checkering and dual beads that has been hunted hard for decades, most of the finish is gone, and cheering is worn smooth for the most part but lockup is as tight as new guns,
