Sighting in a Buckhorn

[EEB]

Hello - I'm a new member with a question about the most efficient way to zero a buckhorn sight. I shot Trapdoors 15 years ago and enjoyed the history around them, working up loads, etc., but they kicked the daylights out of me. Sold them and put black powder aside. I got the itch last year and began my search for a modern rifle. I just took delivery from a vendor on one of the auction sites of a C Sharps 1875 with 34" barrel. The 11 lbs should absorb a lot of recoil. No loads have been worked up, but I will start with the ones I used in the Trapdoors (500 gr Gov't bullet, 68-70 grs. 2F, card wad) The C Sharps sight has no markings; where should I start? Should I start very close with the sight bottomed out (< 100 yds) and work my way back to 200 and beyond, or is there another way? I have no experience with these type sights; the Trapdoors were fairly straightforward to zero. I am probably making this more complicated than it is, but what would be the recommended method. Wonderful site by the way. Thank you.