Thanks to everyone who gave me suggestions on fixing the Walker. I have done a repair on it, shot it and it appears to be functioning very well. This repair is fairly easy to do, here is a short description of what was done.
For this description, I will use the part #’s that appear on this exploded view diagram of the Walker found here -
http://www.gunpartscorp.com/Manufacturers/Uberti-33543/Revol... This is the best such diagram I have seen on the Walker, thanks to No Deer for sending along this link!
The arbor, or base pin #21, is screwed into the revolver’s frame #1, the rear of it can be seen in the hammer channel at the rear of the frame. The arbor is held fast in this position by means of another pin called a cylinder lock pin #28. This pin is inserted into a hole drilled into the threads of both the arbor and the frame. This pin is peened into position. In the case with this revolver, it was this pin that had worked itself loose, probably from several hundred magnum rounds being run thru it, and it was allowing the arbor to move slightly.
To repair this issue one must first remove the cylinder lock pin #28. The diameter of this pin was .117”. Use a drill bit smaller than this, I used a #35 drill bit, and carefully drill into the end of the cylinder lock pin. Once about ¼ of the pin had been drilled out the pin was easily removed. At this point the base pin #21, was easily removed from the frame by unscrewing it.
I cleaned and de-greased the threads with acetone, applied Lock-tite to the threads and screwed the base pin into the frame until it was seated back in it’s original position. At this point it is important to partially re-assemble the revolver by putting the barrel assembly #3 back onto the frame and inserting the wedge assembly #4. Doing this while the arbor is still loose ensures that the barrel and frame will line back up on the barrel pins #23 at the front of the frame. If you fail to do this, it is possible to set the base pin #21 in the wrong position and it will be .almost impossible to re-assemble the gun after completing the repair and tightening up that part.
Now with the gun partially assembled, barrel and wedge in place, cylinder still out, you will need to re-insert a new pin to replace the old cylinder lock pin #28. In my case I did not have any .117” mild steel stock around the shop, but I did have plenty of .125” stuff. I carefully drilled this hole out to .125”, then cut a small piece of the .125” round steel stock to a length slightly longer than the depth of the hole then filed a small taper on the forward end of this pin. The pin is inserted into the hole and tapped in as far as possible. I then used a center punch to drive the pin home further and bulge it slightly. The end of the pin is filed flush, a #2 pillar file was perfect for this. Finally, using a very small cold chisel, the rear of the new cylinder lock pin is stuck, peening the pin and the frame together. Two peens across this area was all that was needed.
At this point the gun was tight, the wobble in the arbor was gone. I let the Walker sit for two days allowing time for the Lock-tite to fully cure. I took it out and ran three cylinders thru it with 50 grains of 3F Swiss and a .457 ball. It is now again holding a 2” group at 25 yrds.
In researching this problem last month I found several people who have had the same problem with a Urberti Walker. In one case someone mentioned that they had actually retired the gun and bought another. Hopefully what I described here may be helpful to someone else in the future and keep one or more of this fun to shoot revolvers from going to the bone yard.
P.S. to Zonie ”“ I do not plan on selling this gun, it’s too much fun to shoot and hunt with!