The original barrels are 20" that the owner wanted to keep. So we made a new monoblock. The new 50-140 barrels ar 28" with express sights. 1 standing 2 leaves. There is a short quarter rib which the sight is dovetailed into. Then hollow rib from there to front sight. I was afraid of balance because of the 28" barrels. However I profiled the barrels using some of the info gained here and they are .110 wall thickness from about 14" out to the full 28" Then with the addition of pad the rifle balances pretty well.

The one we used had just a little roughness in the sears. We stoned them a bit and rehardened the surface. Smooth now, very smooth. The only thing I don't care for is that the hammers seemed to be angled out just a little bit. I think that could probably be worked out with out much issue though. Since the guy who was footing the bill didn't mind we didn't play with that at all.

I have one sitting under my bench for a furture build but I found a nice older hammer gun to use for a build first.

I'd be interested in hearing how your build progresses.

Bill