Several Questions

[frogwalking]

I have an old Craftsman lathe, only a 3 jaw chuck.  I also have a 5 inch long 1 inch octagon cut-off from a rifle I built years ago.  (The barrel came from Tip Curtis and I have no idea who made it.) I have a piece of brass rod 9/16, I think.  I have turned a piece of the rod down to .5650 so it is still a little too big to go in the bore.  I have a 3/4 16 tap, so need to cut a hole 11/16 by 1/2 inch deep in one end for a breechplug I don't have yet.  Now the questions:  I heed to temporally attach the brass plug in the muzzle end of the barrel so it can be centered in the lathe.  I am considering three methods: 1. try to cut the brass slightly oversized, heat the barrel and shove the plug in'  2. cut the plug to fit and epoxy in place,  Heat to remove.  3. soft solder the plug in the barrel and later, try to get the solder out of the barrel.  I am not sure how to get the brass out if I use the first method  Can I put the 11/16 bit in the chuck of the lathe and drill the hole for the 3/4 inch tap?  If I ruin this thing I am out approximately nothing.  I am starting to make a pistol to keep myself amused while I wait (apparently a long time) for a queen Anne pistol kit ordered from Blackley in England months ago.  They are quite nice but apparently are having labor issues with Covid.  Oh, I really don't know how to use the lathe either, so am faking it.

Thanks,

Frog

[HobbyJumper]

I'm suggesting you watch a few basic lathe tutorials on Youtube. Start with one called Blondihacks. She explains the operations very well.

[Long Ears]

I must be missing something here. Why do you need a rod to center the barrel in the lathe? Just chuck the muzzle end in the lathe chuck and index it in. Use your tail stock and drill and tap the breech. If you use a live center in the tail stock it should indicate in pretty easy if your head and tail stock are aligned properly. Use pieces pf brass in the 3 jaw so it don't mark up the barrel. Then buy a 4 jaw off of ebay... Bob

[Bob Roller]

An octagon barrel in a 3 jaw chuck is not likely.A round or hexagon shape would work
OK but hex barrels are all but non existent.The rod in the muzzle end can't work either because the torque of the lathe
will cause the barrel to slip during the drilling action.
Bob Roller

[frogwalking]

Thanks Bob.  That was the plan, but apparently won't work.  Another possibility is to hand file the barrel round.  That would keep me busy for a while.

[mark brier]

Pretty simple to do turning between centers especially if you have a live center and a taper attachment if you are tapering the barrel. For the breech end I made the common 5/8 and 3/4” thread sized and about an 1” long then flip  it around and indicate it in and use a center drill. Simply screw into breech take your chuck off and put on your drive plate, pretty simple then put your drive dog on and set it up to turn between centers. No plug needed for muzzle end if you have a live center, just make sure your tail is aligned if you have a taper attachment or if your turning it by offsetting the tail stock figure out angle and set it. I’ve not ever messed up a crown being on a live center but you can always redo the crown at the very end if needed.
Mark Brier

[Bsharp]

Build yourself a 4 screw spider.

Or find a 4 jaw chuck.

Search:   lathe spider

[Scota4570]

You need a 4-jaw, a face plate, and some lathe dogs.  Look for a used machine tool dealer and buy what you need.  The 4-jaw is not strictly "craftsman" the backing plate is.  Get a backing plate and machine it to fit the 4-jaw you find.

Also get a decent dial indicator with a magnetic base and a set of digital calipers.   I also suggest getting a Phase 2 tool holder set.  The old type Armstrong types are a pain in comparison. 

Regarding holding your barrel between centers with what you got.....  Make a breech plug bolt with a center hole.  Turn a center spike in your 3-jaw, do not break the setup.  Drive the breech end with a lathe dog running against one of the jaws.  Protect the flat with a penny.

Turn a snug fitting brass or aluminum  center bushing with a shoulder to fit muzzle. 

To turn a taper offset the tailstock toward you the desired amount.     For long barrels you will need a steady in the middle.   

Good luck

[JPK]

To hold the octagon barrel in a three jaw take a piece of aluminum that is 1” larger then the barrel. Chuck it up and turn the OD to just clean and bore a hole in it that the barrel will just fit in. Make it about 1 1/2” long then saw a slit in one side along the length. This collar will slide over the barrel and can be held by the three jaw for doing the breech ing. Aline the slit between the jaws rather then a jaw pressing on the cut.

[Not English]

Frog, with only a 3 jaw chuck maybe your going about it wrong. I'd suggest doing it with a drill press or mill. You don't have a very long piece of barrel, so it should work. You need a V block to clamp the barrel up vertically. If you have a milling machine it's easier, but it can be done on a drill press if the V block is clamped up very securely. Make sure the barrel and clamp assembly is centered and won't move. Then drill slowly to keep vibrations down. I don't have a lathe, so I've had to think differently. I've done this successfully when making ramrod extensions, so it should work on a short barrel that will be stiffer than a 3/8 steel rod.

Dave