T grade 1885 Parker

[Frank Danner]

I have an 1885 Parker T grade with reverse chokes. No, not switched left to right, but
instead of a constriction, the chokes open up, like a Blunderbuss. They measure as ten gauge chokes, the shotgun is a twelve gauge. Has anyone seen this?

[B. Dudley]

What is the bore diameter and choke constriction?

[Frank Danner]

At the end of the barrel, right .758, left:.754, I have no way of measuring nine inches inside the barrel to obtain barrel inside diameter. I assume it is the 12 gauge standard 729-.730.