I do mine a lil differently than Ken does, but results are the same. Inlet the barrel & tang & 1 tang screw to lockplate in, get the barrel pinned in, lock in, trigger in, buttplate & toeplate on. Then I make the extension for the tang & take the tang off the barrel.
The reason I take the tang off is because it is
very easy to keep bending the extension when you have 44-46-48" of barrel on the other end, and not want to bend it, and believe me that sucker catches Everything.......
Thus I take it off & deal with 12-16" of metal rather than 60" of metal at a time.
Take the tang & extension to the welder & weld them together & make sure they have a lil extra support under the joint & taper if toward going out the extension.
Take the piece back, clean up the welds to the shape I want, heat it & anneal the weld, drill pilot hole into boss for screw, bend the extension up behind the boss where I want it, inlet that part of the extension. Then I bend the over-the-comb part & inlet it.
Put the buttplate up over the extension & mark where it will butt to it. Take the tang out of the inlet & cut it off, saving 1" of the part I cut off. Put the whole tang back in & check measurement again at buttplate, take back out & grind then file to ? .025 of where I need the end to be. Take the 1" piece I saved off the extension & out 1/2" of it under the end of the extension & silver-solder it on the end. This is the lip that will go under the buttplate to hold the rear of the extension down & in place.
File clean it up & back to the stock for final fitting, buttplate on & file fit til I have about .010 clearance between the buttplate & the extension, fit buttplate back on & insure everything goes where it is supposed to.
Take it out & put the tang back on the barrel & back in the rifle, clamp boss & on drill press with drill pilot, drill boss hole & countersink & then tap hole & install screw & cut off excess.
Now I do the final filing down on the extension & final shaping, etc.
It is
Imperative that you refrain from bending the tang upon installation & removal every time. If you bend the extension & straighten it, the metal grows in Length & now it won't fit, as the boss has moved.... This means shrinking the extension in length or cutting it off & reweld it, or making a new one, or having sloppy inlets, etc. Thus it is time consuming & frustrating, and if you are not a patient person, this may not be something you want to start. Once you make that initial cut down the comb, you are committed......
As for it being a useful item on a rifle, I can find no use for it other than it protect the top of the comb & point of the comb a tad, but not a protection from anything major. I feel it adds no strength to it as it is too small a piece to give any noticeable strength because it is mild steel & small/thin. However it is an appealing feature that I like, thus why I do some of them....