I am looking at installing such a sight on 2 rifles, an old but nice Winchester 67 with a 27" barrel, and a n old Stevens 66B Buckhorn. I have redone both and they are excellent.
The Winchester has a dovetail rear sight, and the Stevens has a receiver mounted peep. however, the Winchester rear sight is too indistinct, while the receiver on the Stevens blocks too much view, with that big, black disc.
I had put a Marbles on the Stevens. It had a dovetail cut in the top of the barrel, which was too narrow.
I opened it with a file..a loose fit, but it worked..for a time..but then I lost it.
With that Marbles Bullseye, I may as well had a scope on it! I went my local club range, and using some unbroken clay pigeons..it was easy at 50 yds, to smash the clay...then just as easy to pick off the pieces of the clay, one by one..
I will next time however, have a dovetail cut professionally.
Thanks again, for the brush up, guys...