Threading first Barrel help

I just got my first lathe and have limited machining experience. With that said i am ready to cut some rifle barrels down and thread the muzzle for suppressors.
I know that trusting the OD of the barrel to be concentric to the bore is not wise. I also know the "best" way to turn a barrel is to use 1 dead center in the breach end and one live center in the muzzle with a lathe dog turning the barrel. My lathe is not large enough to handle such a task. If I chuck the barrel through the head in a 4 jaw chuck indicating off the OD to get close and use a Live center in my tail stock, will this bring me accurate threading concentric to the bore. Also if it will should I push the barrel as far through the head as I can (allowing a longer distance between the chuck and tail stock) or should I keep it a short distance for rigidity?

Thanks

Treading and chamber reaming is not a novice project.What caliber are you trying chamber.

Read his question- He is wanting to thread a muzzle.
OP-NEVER trust an OD for anything. As you pointed out they are very rarely concentric to the bore.
Here is how I do it when I "pass through" the barrel through the headstock:

I use my 4 jaw and I wrap a single coil of #6 copper ground wire around the barrel. This serves two purposes-1 Protect the barrel finish 2 Acts as a pivot point for the barrel.
The outboard end is supported by a "Spider" (If you dont know what it is-find out and make one-you need it for barrels). In short it acts like a 4 jaw on the out board end.
Chuck up the barrel and rough dial the bore in. When you are roughed in then take an "Indicator/range rod" and insert into the muzzle. Using your indicator on the rod near the muzzle zero it in. It helps if you have a second indicator on the far end of the rod as well but you can do it with one indicator-just move your carriage.
You are going to manipulate the 4 jaw and the spider to ZERO movement of the indicator needles on the range rod. It will vary from barrel to barrel-some barrels I can dial in a few minutes but I have had others that took nearly an hout to dial in. It is a PITA but for QUALITY barrel work a must.
You now will have threads that are concentric and axially aligned to the bore. This is absolutely essential if you are threading for cans. A .002 error at a muzzle is a .020 error 10" from the muzzle. You will suffer a baffle strike on a can! (Dont ask how I know)

If you dont dont have range rods and such then do yourself a favor and dont tackle any barrels until you have the correct tooling.
If you are forced to support a barrel between centers for turning/threading make a "False Muzzle" out of aluminum or brass that slip fit pilots in the bore and is centerdrilled. Insert it into the bore and let your live center bear against the false muzzle-that way you are not running a hardened live center into a fairly soft muzzle crown. Dont try to cheat and just run the live center-you will eventually have it loosen up and spin the crown against it.
Then you get to recrown a barrel for free!

Good one

Great post and good advice.

The previous post covered things well.

Is it safe to assume you have chased threads before and have a typical technique that works for your machine?

If not, a barrel muzzle is no place to work the bugs out of your threading procedure.

Be sure your threading tool is correct for the job at hand and sharp.
Take the time to verify the OD tolerance of the threads in a proper reference, like the machineries handbook. Turn the OD carefully before starting to thread, and cut a proper relief cut at the end of the threads so you have a place to pull you tool out when you stop threading.

If possable have a check gage or the real can to verify your threading before removing parts from the lathe.

Working close to the chuck increases the stiffness of your set up, and will make it a bit easier to stay aligned. No matter how well you dial in, your cutting will deflect the part some.

Take light cuts and use a thread gage to verify the pitch of the threads after the first pass. Its easier than you think to set things up wrong.

Excellent advice. I remember a retired machinist who posts to this site who has forgotten more than I'll ever know about machining saying that if he hadn't threaded in awhile, he would take a piece of scrap and do a practice piece. While threading is pretty simple, there are several things that must be done correctly pass after pass. I remember one time I forgot to check that my threading tool was centered on the piece to thread. After all it was on a quick change tool post and it had been correct before! Well, it had gotten moved and was off enough to ruin my thread. Little things like that can ruin a job and a barrel. Especially if the barrel was already 16 inches! ;-)