View Full Version : Lathes for gunsmithing
08-19-2001, 04:08 PM
What would be an appropriate size lathe for general gunsmithing work? Work like chambering and threading barrels, crowning, facing actions, etc. Not necessarily barrel "turning" as you can get just about any profile barrel you want. I know that the spindle hole size is paramount with the swing over the bed much less important.
And secondly, would you suggest a used older South Bend with a small spindle hole or a new "oriental" machine with a signficantly larger spindle hole?
Obviously, I'm not a pro, just a serious amatuer looking for something to keep me entertained and productive in retirement.
I'd definitely go with a large spindle hole; anything that takes a 5C collet ought to be okay, as that typically means a through-hole of around 1 3/8" (5C collets go to 1 1/8", if memory serves).
I'd also look for a long bed lathe that will typically take 36" or so between centers. If you could find a long bed South Bend 10" lathe, that would be really good, I think. (n.b. the "real" SB 10" lathe, not the SB 10K, which uses a 6K collet). The SB 10" lathe also has the so-called wide range gearbox that lets you cut additional screw threads, like 30 tpi, that the standard quick-change gearboxes can't do. I know at least some Lyman reloading equipment is 30 tpi....
Yes, a large spindle hole is important, more so than a long bed. There are several ways to set up a barrel. One good one is to chuck the muzzle end and use a steady rest. Another, if the headstock/spindle is not too wide, is to construct a spider at the left end and use a chuck on the right. Both carefully done can dial to .0001-.0002" fairly easily.
Some people insist that the only accurate way to do barrel work is to be able to indicate on the actual bore which may (probably isn't) or may not be true to the outer surfaces of the barrel. That can be done by working between centers for threading (which may need a longer bed lathe) or it can be done by gauging on the interior of the bore by using long pin gauges and the previously mentioned setup.
This fellow, one of the best, is nice enough to provide descriptions of how he does his work:
08-27-2001, 05:58 AM
Steve Acker has a new gunsmithing book from HSM - it may be helpful to you.
Find yourself a used machine in good shape (American, British, German, or Canadian) and you will be happier than with a cheap import. If you look for a machine with a MT#5 center in the headstock you will have a large bore and can use 5C collets with a cheap adapter (ROLL YOUR OWN). A good precision steel chuck with removable hard jaws and machinable softjaws (to properly grip the barrels)is a great accessory, but you can get by with cheaper gear.
Check out auctions and bankruptcy sales - with patience you will find a great machine eventually. You would be better off with at least a 36" bed as SGW suggested - you say you do not want to turn barrels now, but if you are serious about the gunsmithing you will later...
[This message has been edited by Thrud (edited 08-27-2001).]