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Headstock bigger than my barrel

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  • #31
    I've done that with carbine length barrels with excellent results.
    Ignorance is curable through education.


    • #32
      Thought I'd close this thread for posterity, or hopefully for the poor sucker who is looking for a solution as I was back in August.

      Here are some pics of the setup I ended up using. By mounting a large, double ended spider in a 4 jaw chuck I can first dial in the spider, then dial in the barrel via the 8 brass cap screws. The spider I made from two pieces of scrap stock welded together then turned. I drilled the holes that you see so that I'd have adjustability. It' hasn't been needed. The brass cap screws are from McMaster. By using an indicator rod ordered from Brownells, I can indicate to the exact bore of the rifle barrel. It takes some patience to get everything trued up and watching a video from Smartflix called metal work for gunsmiths or something like that shows some really good examples of how to do it.

      This setup allows me to use the tail stock for extra rigidity while threading, then I simply recrown the barrel as a last step. It is easy once everything is set up.

      Many thanks to all who helped me onto the correct path.

      And here is what a finished product looks like.

      Dan from Raleigh, NC

      If it's stupid but it works, it's not stupid.
      "What is your host's purpose for the party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have sent champagne and women over to your place by taxi." P.J. O'Rourke


      • #33
        There is yet another way, but it will involve a steady rest. Make up a spider like MrDan's, and indicate it on your barrel that's between centers. Set up the steady rest on the o.d. of the spider. The muzzle end can be bungee corded via a lathe dog to the face plate to provide tight pressure against the dead center in the headstock. The breech end is supported by the steady rest via the spider. Make your spider big enough and you can also use it on octagon barrels. Before starting to cut threads or cut your chamber, indicate the bore to make certain that everything's going to run true.

        David Kaiser
        “You can have peace. Or you can have freedom. Don't ever count on having both at once.”
        ― Robert A. Heinlein


        • #34
          I know it's real late to reply to this thread. I found it looking for a solution to a similar problem, and then enjoyed reading how others solved this problem. In the interest of helping others who might have this problem I have two suggestions that have not been mentioned.

          Buy a thick back plate for your lathe. Drill and tap it radially for four brass tipped 3/8 screws that act like a FRONT Spider. A back plate is usually a good 4 plus inches thinner than a four jaw chuck. A front spider is actually better than a four jaw because the screws also allow the barrel to pivot like a gimbel so the barrel bore can be aligned.

          If the way the backplate attaches to the spindle makes it impossible to center all four screws at 180° intervals (eg D1-5 cam lock or long nose spindle), then attach a 5/8" or 3/4" face plate to the backplate and drill & tap that for the four Spider screws instead. Either way, the idea is to get the front Spider and therefore the work, as close to the nose of the spindle as possible.

          Yet another approach is to make a double Spider that mounts to the four jaw or that is mounted to another backplate (mounting it to a backplate with rear through bolts is much more rigid). This is essentially a piece of very thick-wall pipe with flats for the chuck jaws at one end (flats are not really required), 4 brass tipped screws just ahead of the jaws, and another 4 screws at the outboard end. (maybe I should call this a true Spider since it has 8 legs...... LOL) If the double Spider is attached to its own backplate, then it essentially becomes a new double Spider chuck to be used in place of a four jaw or three jaw. Although I have not done it, I suppose it could be drilled and tapped for yet another set of brass tipped screws to be a "triple spider"

          Like the OP, my lathe has a wide headstock. But I have used both methods with great success. I prefer the former for precision barrel work, but the latter works well for mounting actions and very short barrels too.

          One last comment - in hind sight, I wish I had used 7/16-20 cap screws for the spiders. If I had done that, each full turn would have been 50 thou. A good thing to know when first roughing in the alignment.