Okay----well aside from the general shape which most certainly resembles the Paine Black Bead, it isn't.

As to what it might have been before it was attacked by what appears to have been a very angry beaver is anybody's guess. Stroebel's Old Gunsights-A Collector's Guide, 1850-1965 shows several possibilities; only one of which is designated for use with a handgun (and unlikely). The most likely others are labeled as carbine sights (with available bead diameters of 1/16", 3/32", and 1/8"), so if what you're seeing as a bead seat is compatible, then--------maybe. (The standard Lyman bead was ivory---gold, red, and silver were options. The bead diameter on S&W's in my collection which carry Lyman sights is .060".)

So much for what it might have been. What it almost certainly is not is anything that ever saw the inside of S&W's plant (and that's based on the Bubba job on the pin). If you wish to restore the front sight to what it most likely was when it left Springfield, the so-called Thin Round Top Blade is your best bet---standard on S&W HE target revolvers from 1905 to 1923. The height should be that which stands .318" above the base.

Ralph Tremaine

As an aside, the Thin Round Top Blade is as common as dirt; and should be readily available from the sight folks (George Dye, Don Mundell). If not, it should be child's play to make; and I'll be glad to pull one out and provide a drawing/tracing/dimensions.