I have a Sig P-210-6. I bought it new in box last year, but it was made in 1978. Sig or the distributor apparently has a bunch of the older ones stashed away, somewhere.
The proof target (from the factory) that came with it shows an under-1" group at 50 meters (about 55 yards, I think.) I can't shoot that well.
It'll eat anything. And, as far as I know, they're still being made (but not a lot of them), so parts should not be a problem. I have yet to hear of one needing parts...
Mine is very accurate. The trigger is a joy. I have used it in IDPA competition. Because of the light trigger, when I tried to shoot fast while practicing, I often let off a shot early. In actual IDPA drills, however, this has never been a problem!?
Happily or unhappily, while it is a superb gun and very accurate, I'm able to get about the same accuracy out of my Glock 17. (I think I'm blessed in having a very accurate factory-refurbished Glock 17.)
Where the experts say the Sig P-210 excells is at the longer distances -- as it apparently shoots a very flat trajectory.
The big problem is the price: I got mine for $1350 -- and that appears to have been a pretty good price for a NEW one. You can buy a lot of guns for $1350. (If I had not just come into a small inheritance, I'da never have done it.)