I have a fully rifled slug barrel on an 870 action. It is the one with the iron sights. I would like to be able to use it with a scope. Are the remington cantilevers available as a part, and I suppose they are soldered on the barrel, or are they somehow tack welded on the barrel?

I believe the barrels are drilled and tapped but not all the way through. The holes close to the receiver where there is more meat and the chamber/barrel pressures are so low there is little to no risk.

Does anybody know if they are available as a part.

http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=10069

$45.00 from Brownells