This is what I have. Labeled as Trapdoor safe and lots of good reviews, but I don't see any reviews mentioning either the 1873 or 1884. This ammo is 1500fps and 350 grain bullet. Should be safe?
You may need to make/order a replacement front sight blade. I make all mine from the banding on Greek 30.06 cases. Sand off the galvanization, cut and shape with hand files, drill and replace the short sight that was original (if that type). Cold blue to color it black. Or, if you're not quite that much of a Scotsman, order one from S&S Firearms, NY. The short front sight blades were needed for sighting in at longer ranges with most rear sight types.
Add: You'll want to start high, about .2" and for that blade, with your preferred load, zero by setting the rear at the lowest setting and then filing down the front blade until your POI is raised to the desired location in your target (assuming a 100 yard range here).