Gentlemen,
If you are thinking about doing a project gun this fall or winter, I still have these ribs for sale as well as hollow bottom ribs to match. These can be put on at least two ways, you can either butt fit them up to the short top rib on your monoblock, or you can machine that part off and overlay these full length. If you do machine off the top rib section, be sure you still have enough contact left between the two sides to hold it together in cases where it was made in two pieces.
I have also left part of the top rib when it was narrower than the new rib and machined a pocket in the bottom side of the top rib so that the new one would fit snugly down over it. Either way makes a nice looking rib without any joint in it. The new bottom ribs are hollow formed to match the hollow ground portion of the top ribs and work very well together. I am keeping the prices the same on all these even though the costs to me have gone up.
I also have some E.R. Shaw 12 gauge rifled barrels for sale that are plenty large enough to monoblock into a 12 gauge frame, they measure 1.1 inches at the breech end and are 24 inches long. By the time you get them monoblocked into your gun you will be able to have a 23 3/4 inch long set double rifled barrels. If you thin them down properly, you can end up with a rifled 12 gauge double that weighs between seven and eight pounds, finished, and it will have the proper balance. These barrels are price cheaply at $100.00 each plus shipping and make up into excellent rifled guns.
I have just a couple pairs of Verney Carron 20 gauge rifled tubes left at $300.00 per pair, plus shipping. The are 30 inches long and are full sized bull barrels and are big enough to use with a twelve gauge frame and monoblock. I have found it wise to monoblock both the 12 gauge and the twenty gauge slug barrels into 12 gauge framed guns. This is so you can get the right amount of weight in each gun to help with recoil control. Twenty gauge barrels, properly profiled and monoblocked into 12 gauge frames make a very streamlined and elegant gun with the proper weight and the balance placed correctly between the hands.
You can look at my past postings to see these product in use on guns I have made. The top and bottom ribs together make for a very strong barrel set construction, especially if soldered with Brownells Hi Force 44 solder, and they will save you many hours of construction time plus they are nice looking. Bob H.