The factory BC sights will work fine if (big if) they put the correct height front sight in it, many, many have come with too high a front sight to zero at 100yds, that's prolly the biggest reason for changing the front sight, that and globe sights aren't great for hunting in low light conditions, great for target work tho. The Williams WGRS rear sight is a bit tedious to adjust, but once adjusted works fine, I have them on all my muzzleloaders incl my Huntsman and one of my 45-70 Handis, although I have changed the aperture to the twilight which has a bigger hole in it, see Peep and Firesights in the FAQs sticky, it can be used as a ghost ring without the aperture or you can buy a ghost ring for it for $5. There are some other great peep sights tho, Skinner(site sponsor) and NDS for a couple that many here love.
Tim