Thanks Tim,
You are a fountain of knowledge about these guns. I guess when you have so many you learn a couple things...
One more question. What's involved (tools etc.) with tapping a screwhole for a front-sight? Are the 44s cheaper when they're on the SB1 frame? Was that two questions?
Drilling and tapping isn't hard, but you only get one shot at it, I've done it by hand, but a drill press is a better choice, getting the hole drilled in the right spot and true up and down is the hard part, and only deep enough to clear the screw length, all ya need is a tap or two and the correct size drill, the Williams shotgun shorty ramp fits the 44mag/45-70 barrels perfect, they come with a 6-48 screw, ideally a taper tap would be used to start with, then a bottom tap used to finish the hole, but the taper tap could be used by itself, Brownell's sells the taps and drills necessary for the work if you don't have a shop locally to buy from, 6-48 won't be found at your local hardware store, but you could use a different screw size, 6-32 would be a common one, you'd need a tap handle too.
SB1 frames cost less, they're cast iron, no heat treating, SB2 are heat treated investment cast alloy steel.