Is this a viable procedure of machining a simple barrel from a barrel blank ?
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    Question Is this a viable procedure of machining a simple barrel from a barrel blank ?

    So i want to make a very simple barrel(no lugs/no different diameters across the length), basically just a cylinder that is let's say 145mm long.

    I have a 23mm diameter 9x19mm barrel blank and it is 550mm in length.

    Now do these following operations make sense to you ?

    If not please correct me, if yes please confirm that my steps are correct in theory.

    1. I take the barrel blank and put it into my chuck in the spindle and the other end stays free, but since the barrel blank is so long i'll use a steady rest on the other end.(my spindle bore is too small to have the majority of the barrel blank stay at the spindle end of the lathe)

    2. I now cut a little bit longer than 145mm piece of the barrel blank off with a parting tool, I use cutting fluid and slowly but steadily cut into the blank so that a 145mm piece of the barrel blank almost falls off. I use a hand saw to cut the last bit off.

    3. FIRST QUESTION: Now here is a question i have at this step: Do i have to cut a 60° chamfer into both ends of this barrel blank piece before i can work it between centers ? If yes does that mean i will then have to mount the left end into the chuck in the spindle and with the help of a steady rest on the right, i then drive the 60° chamfer mill head which i have mounted in the tailstock, into one end of the barrel, then i take out the barrel, turn it around, and add a chamfer on the other side as well ?

    4. Now take the chuck out of my spindle and replace it with a in my case mt3 tapered dead center, use a threaded hole at the spindle to screw in a screw, butt end of the barrel against the dead center and now use a lathe dog that i secure around the barrel and which butts against the screw that is mounted around the spindle.

    5. I put a live center into the tailstock, in my case with a mt2 taper.

    6. I use a dial indicator to make sure that the centers run true, if not look if cleaning the taper hole, and putting them in again, helps.

    7. I now put the barrel between the centers and can now turn down the barrel to my desired OD.

    8. Now that my desired OD has been reached, i take out the spindle center and put in the chuck again

    9. I put the majority of the barrel through the spindle, since the OD does fit through the spindle bore now and mount it, making sure the dial indicator says the barrel runs true to center when the spindle rotates.

    10. QUESTION: Now here comes another question that i have, would you recommend i use a boring bar now to pre bore the chamber 0.010” undersize or not ?

    11. I then take out the barrel and mount it into a vise with the muzzle end pointing to the floor and ream the chamber carefully with a tap and a 9x19mm finishing reamer ( i don't have the tools to mount the reamer properly into my tailstock( like a floating reamer holder).

    12. Now i'm basically done and can add things like turning a section at the muzzle end down so i can thread the muzzle and also, in my case, add a chamfer to the chamber side for the cartridge to go into the chamber properly, which i need for my specific gun design the barrel is intended for.

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    Sounds like you need to let someone who knows what they are doing...with the right equipment, do this.

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    Really constructive feedback you gave there ...

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    Quote Originally Posted by RiflingBob View Post
    Really constructive feedback you gave there ...
    It may save your life

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    Quote Originally Posted by plastikdreams View Post
    Sounds like you need to let someone who knows what they are doing...with the right equipment, do this.
    Quote Originally Posted by RiflingBob View Post
    Really constructive feedback you gave there ...
    Actually he is 100% correct
    , not so much on the right equipment but more on the
    "Sounds like you need to let someone who knows what they are doing.." part

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    OK, speaking as a gunsmith here...

    I'm not going to get into nitpicking details of the gunsmithing end of this. I'm going to back up to the 10,000' level.

    First comment: It is clear to me from your question(s) that you haven't much machining experience on a lathe. This isn't a criticism - everyone has to start somewhere. My advice, which is worth exactly what you're paying, is that you not start your learning how to machine on a lathe with an expensive piece of steel, ie, a barrel.

    Second comment: You're not specifying how the barrel will mount into whatever receiver/action you're going to be using, and that's an issue you need to resolve in the order of machining operations here.

    Third comment: I'm not sure you realize how much the exterior of a barrel can be non-concentric with the bore, and you didn't give indications that you have the proper tooling to indicate in the barrel on the bore for certain operations.

    So, my $0.02: I would start with having you machine up a long piece of 4140 round steel that isn't a barrel to learn the speeds, feed and order of operations before you set to working on a much more expensive barrel.

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    How are you going to cut the rifling groves inside?

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    Quote Originally Posted by rons View Post
    How are you going to cut the rifling groves inside?
    he's not he bought a barrel blank already has rifling in them.

    He needs to hook up with someone and watch before he touchs

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    Rifling Bob I think you have thought this out pretty well. Step 1 and 2 are fine or band saw it or hack saw it ect. just get it close to length you can clean it up later. Step 3,I would cut centers. A piloted center drill is one way but since you have a lathe I would indicate the barrel in a four jaw using a pin gauge that fits the bore or a dti and read directly off the bore. Once you have indicated the bore set the compound and with a small boring tool cut the chamfer on the barrel face it square at the same time. Flip it around and repeat. Steps 4-7 I would turn the od between centers couple ways to do it I would chuck up a pc of stock and turn a center in the chuck now you have a perfect center at the hs put the barrel between centers an take a cut check for taper adjust if needed and then turn to dimension required.
    step 8-9 Since I dont know how true your chuck will hold the blank in term of annular alignment I would suggest you grab the blank in a 4 jaw and use a live center in the opposite end. Indicate the chuck side true and install your steady on the od of the barrel at the chamber end. I probably would not prebore for a 9mm pistol chamber but you certainly could if you wanted to. As far as reaming goes you have options here as well. Floating holder, floating pusher, drill chuck ect depends what you are comfortable with

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    If you can cut it off square, chamfering the bore with a countersink (just break the edge) will let it run true enough on centers.

    Dialing it in and boring them might be a bit better. But you might be surprised at how good a light chamfer will do.

    Once you've got the OD true, put the muzzle end in the chuck and the other in the steady rest. Support the reamer on a center and cut it to depth.

    Kinda like it was done, and still is, for a hundred years plus.

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    I agree with those who say you should get on the scene help, but if you do it yourself, lay a piece of wood on the back way behind the cutoff point. When the hacksaw goes through, it often will go on down and hit the way, putting a notch in it. It happens so fast that you may not be aware of it.

    Bill

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    Classes can be cheaper than screwed up rifles.

    NRA Explore | NRA Gunsmithing Schools

    NRA classes at TSJC is how I got started in this trade. If nothing else it makes a nice vacation, in my case I went back as a full time student.

    Sent from my Pixel 2 using Tapatalk

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    Taking classes is a good idea.

    The book by John Hinnant is an excellent step by step guide to fitting a rifle barrel. Very detailed, explains everything from tooling, fixtures and procedures.

    JOHN HINNANT THE COMPLETE ILLUSTRATED GUIDE TO PRECISION RIFLE BARREL FITTING | Brownells

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    I think the initial post has all the necessary then some......no need for any reamer for a 9mm straight case,small boring bar job.....However ,my question is whats it going in?....... 145mm long.....cylindrical......maybe he's going to stub a C96.....I hope he s not planning something illegal,like a slam fire SMG.


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