This is just a follow up to my original post since the info was not in the FAQ.
I contacted Williams to ask for assistance on which front sight to purchase. If your rifle measures the SAME as mine, which I suspect all "normal" 22" Handi Rifle barrels will, then you can use this same front sight.
My rifle measures .75" at the muzzle and 1.110" at the point where the WGRS-H&R reciever sight is mounted. With these dimensions, in order to mount a front Firesight, you need a 3/8" shorty ramp and a .312N Firesight bead.
Hope this helps...
Matt