Well I run a 1945 14 1/2 x 7 South Bend it only has an 1 1/8 thru hole. Of course it is belt drive the best thing I ever did was buy a South Bend belt that eliminated the seam. My spindle doesn't show any run out but I don't have a .0001 indicator. I use a 4 jaw chuck 99.9% of time. For barrels that won't fit in thru hole I thread and chamber from centers using a face plate and turning dog. I use a floating reamer holder to handle any small amount of run out that might show up. The one thing I learned was that these engine lathes have to be dead level in all directions or spindle run out will be the least of your worries. And level needs to be checked often especially on a new machine and one that has been recently moved as they tend to unwind and settle into there new position. That being said I don't build bench rest rifles but the vast majority of my rifles will shoot 3 shot clover leafs. Most barrels won't go completely thru my thru hole so a spider won't help. So I have built a set of tapers out of 1 1/8 round stock that I use to center the barrels in the thru hole. There are always several ways to skin a cat so use some common sense and logic to figure out your machining needs.
