I use my Webb 17x40 (Mori Seiki parts-compatible licensed clone) for my own gun stuff. The headstock is deeper than ideal but I’ve made tooling to get around that and it’s awesome in every other way. Overkill is great with machine tools.
It’s almost 5000 lbs… anyway, why I say that is they do have full parts support. I crashed mine once and was really glad for the parts support.
A Heavy 10 is unlikely to have been used for production, which is one way you get bed wear. Another is exposure to abrasives. If previous owner(s) ever used it for polishing, or if it lived in a shop where grinding was also happening, then it’s likely abrasive particles got in between the ways and the carriage and that would do it. Also, I know SB (or at least their competitor Logan) sold some lathes where it was an option whether the ways were hardened. Don’t know if that’s true of the H10. Be extra diligent if the ways are soft.
Some bed wear won’t really matter for chambering; that’s all chuck and tailstock work there. Where bed wear gets you is if say you had to make a continuous, high-tolerance cut for 6” for some reason; if the ways are worn close to the chuck and part of that 6” cut takes place in the dip, you’ll see a difference in final diameter where the carriage rises up out of the dip. Visualize the cutter meeting the work, then dipping down a bit, to get a sense of why the diameter would change. But you won’t be doing that for gun work.
Honestly? I wouldn’t sweat bed wear within reason if your goal is to chamber your own rifles. Threading the barrel tenon is “seat of the pants” type precision; you aren’t measuring so much as cutting the threads until they have the perfect fit to the receiver threads. Nothing about machining the tenon area itself requires extreme precision. What does require extreme precision is the setup. That’s just you being finicky. If you use a good floating reamer holder it really does cure most small stuff- like a slight axial tilt relative to the spindle CL- by itself.
There are guys who hold the reamer solidly in an ER type chuck in the tailstock and then you do need the machine to really “right”. But that’s unusual and not necessarily better.
Scraping ways is a thing for sure but that’s advanced work and opens a can of worms… such as your tailstock not being the right height anymore…
