It is a well used but well taken care of gun. tight as a drum with lever still left of center and as hard as I try I cannot find any barrel pits. I just got around to fully measuring the barrel interior with my Stan Baker gauge.The gauge is very repeatable and I have not noticed any significant margins of error.
After measuring the 30" barrel set here is what I get.
.722 past forcing cone. No variation in gauge
At muzzle no constriction, no choke taper that is none .000
.720 past forcing cone. No variation in gauge
At muzzle -.029 constriction, with about 4 1/2" of choke taper
Other than the serial number I can find no other markings on the barrel.
Cyl on the right and IM on the left? Seems pretty odd to me. particularly for that era? I guess the birds they were shooting were close at flush and straight out greased lightning.
What are your thoughts.