I know there are several vendors who sell excellent quality replacement barrel band front sights with beads, but they do tend to be pricey, and I had 3 carbines that needed beads, so I did it myself. The beads were cut from inexpensive 1/8" brass welding rod. The first photo is my .357 carbine. The bead is JB-welded to the top front of the sight. This works very well at average CAS distances. So I did the same on my 44-40 and 45LC (16" trapper) sights, but both of those shot high, like 9" or so at 25 yards (which was to be expected since they shot high without the beads as well). Since the rear ladder sight is not elevation adjustable, the front sight needed to be taller. So I cut a longer piece of the welding rod to JB-weld to the top of the sight, and now those carbines shoot to POA. The beads really only needed to be filed flat on the bottom but I filed the sides flat as well. The hardest part of these jobs was getting the bead to balance in place on the sight while the JB-weld hardened. Someone with more machinist skills could certainly do a more elegant job, but these were simple, cheap, and do the job.