In conjunction with this pistol grip Hawken I'm currently building, I joined the under-rib permanently to the barrel this afternoon. In the past, I have used one of two methods to do this job, ie: 6x48 screws or soft solder. I joined this one with rivets.
This rib is from MBS and is milled hollow on the inside, with milled concave sides as well. It is already considerably lighter than the cold rolled ribs sold by purveyors of muzzle loading parts. But I have observed by studying photos of original Hawken rifles, that the sides of the rib are usually flat rather than concave. This commercial rib is not only concave, it has a wide flat portion along the edge that contacts the octagonal bottom flat of the barrel. So I glued the rib to a 1/2" rod of steel with CA and filed off the concave and flat to create much more authentic and pleasing side flats on the rib. I polished the sides and the concave rod groove to 180 grit abrasive.
The pegs that will become the anchors for the rib I made from a 3" galvanized finishing nail. I removed the galvanizing with a file in the lathe, then blued it with cold blue to ensure that all of the non-ferrous stuff was gone. The nail finished at .127" I cut the pegs to .430" long, and in the lathe, I made a cut with a parting tool into which the barrel's steel would eventually be staked.
I had to cut off about 4" of the rib to make it fit my project, so I made another peg, drilled a .128" hole through the practice rib, countersunk the concave rod groove with a 1/4" 82 degree countersink, drilled a 1/8" hole 1/8" deep into a scrap piece of barrel stub, set the rib over it, and riveted it down. I'm glad I did a dry run, because the punch I used was not too easy to control, and I ended up putting marks on the rib that would be difficult to remove. The result pleased me in that the rib was very tightly joined to the barrel stub and the rivet was easy to dress off.
So having this success, I proceeded to drill four holes into the rib proper, countersunk the holes, and then temporarily glued it to the barrel for starting the drill into the barrel for the studs. I then removed the rib, and finished drilling the holes 1/8" deep. I didn't bother to make a flat bottom in these holes, though that would have perhaps been a good idea.
With the holes in place, I tapped the pegs into them, and staked the barrel steel down to set them permanently. Then I set the rib over the pegs, and starting at the breech end, riveted the peg into the countersink(s). Once all four were done, I used a rat tail file to dress off the heads, and polished again to 180 grit. I'm happy with the result. ...much less work than soldering.
Here's the same story in pictures...I'll repair the last pictures in a few minutes...
![](https://preview.ibb.co/cbiW9H/100_4015.jpg)
![](https://preview.ibb.co/nrTypH/100_4016.jpg)
![](https://preview.ibb.co/kDTL3c/100_4017.jpg)
![](https://preview.ibb.co/nuY9wx/100_4018.jpg)
![](https://preview.ibb.co/jywwbx/100_4020.jpg)
![](https://preview.ibb.co/iaNDOc/100_4021.jpg)
Two tools that are worth mentioning here, are the staking punch I made, and the method of riveting. The punch is simply an old nail set that is ground off to about 3/32" across the end, with a 1/8" groove filed into a flat that I ground into one side. This enables me to get the punch right up close to the peg, and move barrel steel into the recess of the peg. The riveting was done with two ball peen hammers - a very small one and a bigger one. I held the ball of the smaller of the two over the end of the peg, floating so I could control where it struck the head of the peg, and striking it with the bigger hammer's face. Thus I was able to move the peg's metal into the countersink with some precision, without putting craters in the concave rod groove of the rib.
It took practically as long to type and post these images, as it did to do the job. The next one will go faster too.