After months of On/Off time working on several of Rodney's castings kits, I've been able to make some progress on the first of the 1878 Sharps Borchardt projects.
Previously I had filed and spotted in the receiver shoulders to 90% coverage. Creating a safe (square) edge on the fresh file really helped here.
GT was a great help in working with me to get a lathe fixture setup. This fixture is really rigid and really helps in getting the initial face aligned with the breech block receiver shoulders. Then set this up on the lathe and spent quite a bit of time trying to get my head wrapped around dialing in the face to flat then the barrel bore to centered, then repeating until X, Y and face were spot on. Today was that day where the receiver was "dialed in" to under .0005"

. So I bored it and then threaded it. I had previously made up a barrel thread gauge for testing the threads as I'm cutting it on the lathe... I also have an original Borchardt that currently is apart for rebarreling (to 50-90SS), so that was handy to use for reference.
These picts probably don't look much different than what GT, BobW, Chuckster and others post, but maybe they'll help someone in the future doing an 1878?
Still more to get done - some easy and some not so easy, but to my warped way of thinking - lots of FUN!
Needless to say, I'm quite happy with the journey and the results today.
Cheers!
Jeff P