I'm just playing with an idea at the moment, reaming a .45-70 double rifle out to .45-120 or maybe .45-100.
Problem is, I can't imagine how to how to do it in my lathe. The barrels would fit through the headstock, so unless someone can illuminate me, I think it might be to be done by hand?

Also, and more importantly, what are the chances that a .45-70 double rifle reamed out to say .45-120 will shoot ok?

If a person just absolutely had to do it, and there was enough material to allow it, they could fasten, by what ever means possible, the barrels to the edge of a vertical mill, swing the head over the set, dial in the bore and hand feed the reamer like you would a tap using a center on the quill and pilot to guide the reamer.

That's the way I've done it on a set of 20 gauge barrels.

quote:

they could fasten, the barrels to the edge of a vertical mill, swing the head over the set, dial in the bore and hand feed the reamer

I chambered a .30-30 double exactly that way

Be careful that the surface you locate on is parallel to the bore.

The one I copied was not and had to be shimmed for parallel.

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The one I copied was not and had to be shimmed for parallel.

In response to several PMs received:

Yes, the head of most mills is adjustable for taper in both the "Y" and "X" axis and shimming is not necessary at all.

Make a brass or aluminum shaft to fit the bore lightly and insert it and indicate for straight and then for center and ream on location for each bore.

You will need to circle the bed or indicate a precision square afterwards to re-align the mill but that is not difficult....just a bit of time.

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Originally posted by EXPRESS:
I'm just playing with an idea at the moment, reaming a .45-70 double rifle out to .45-120 or maybe .45-100.
Problem is, I can't imagine how to how to do it in my lathe. The barrels would fit through the headstock, so unless someone can illuminate me, I think it might be to be done by hand?

Also, and more importantly, what are the chances that a .45-70 double rifle reamed out to say .45-120 will shoot ok?

Hold the reamer in the chuck (headstock). Support the muzzle end of the barrel being reamed on the tailstock center, hold the barrels in your hand, and feed on to the reamer with the tailstock quill.
Alternative.
If you have a milling attachment for your lathe, you can set the barrels between centers then adjust the milling attachment vice to hold the barrels in line with the axis of the lathe. This is not real easily done but once it is, you can hold the reamer in the chuck and feed onto the reamer with the carriage or if you set the compound at "zero" you can feed on with the compound.
Another alternative.
Install the faceplate and a center on the headstock. Install a cat's head at the breech end of the barrels and set it up to run true with the chamber being re-chambered. Center the barrel at the muzzle and use a driving dog which is eithr tied to the face plate or clamped, then, with the cat's head running in the steady, chamber conventionally.
Will it shoot? If the barrels are regulated well with a given 45/70 load, they will be regulated with any load which yields similar velocity, recoil, and barrel time. Increase the recoil and decrease the barrel time and it might still work out. Regards, Bill.
PS. I use the first method with one modification. Instead of supporting the muzzle on the center, I turn a plug which is just under bore diameter (about .001 under) and with a shoulder. This supports the muzzle in place of a center so I don't have to worry about the barrels falling down when I back off.

Thanks guys,
I'm starting to get a mental image of how this could be done, I don't have any of the accessories mentioned but I can get to a friendly machinists' and he can help me out.

I'll keep you posted.

or you could just chuck the reamer in the old 12v dewalt drill

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Originally posted by butchloc:
or you could just chuck the reamer in the old 12v dewalt drill

I'll bet that's been done. All someone needs to do is come up with a 3 axis "floating" chuck and bubba is in business...

Someone out there has lathe big enough for this.
There was a guy in the northwest that was set up to do this this.

Why ever go trough the trouble? Ream them by hand! It would be done in shorter time than setting it up in the mashine!

Cliff LaBounty used to do a lot of these. He used a version of Westpac's idea, with an indexable vise setup.

But Why?
Why go through all that setup time, when it is so easily done by hand?

Is it like the story wih the priest and the farmlady? The priest was new in th earea, and went around to visit his crowd. He came to a farm, and was welcomed by the wife in the house.
During tea, he asked for the farmer, and was told he was out in the fields. He asked for the children, and the waife got a mullen expression, but said naught. He asked again, and she barked out unhappy: "If it can not be done with the tractor, it will not be done in this house".

Why? I suspect so the chambers aren't wallered out!

Sorry for being slow, english is not my native tounge. But if you by "wallering out" means that hand-chambering easily screws up the geometry of the chamber, I still do not understand why.
Am I to understand that handreaming is looked upon as a hard thing to do?

No, I would say that hand reamimg is easy to do. But, impossible to run true.

If it's not going to be done right, why bother?

What would be wrong with having a reamer company make up a reamer with a though bolt and index on the muzzle??? Then pull it through, I believe Manson has one for the 30-06?

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Originally posted by Rolland:
What would be wrong with having a reamer company make up a reamer with a though bolt and index on the muzzle??? Then pull it through, I believe Manson has one for the 30-06?

The pull throughs in 30-06 and 7.62 are usually used for setting the final headsapce on semi-autos like the Grand and the M14. They are meant for going very short distance. Taking a chamber from 45-70 to 45-120 would be a freaking nightmare using a pull through.

Personally I don't recommend putting anything down the bore that you wouldn't put in the end of your... well, let's just say I am not fond of putting things down barrels that could possibly cause any damage to the bore. Coated cleaning rods excluded. For the bore that is.

I knew that

Below is a picture of one of the options Bill was referring to.. While it wasn't a chambering job, it should give you an idea as to a basic setup.

Well, I would say that the possibility of screwing up this job in a setup like this is immense compared to handreaming.

The statement that handreaming is impossible to run true, is a bevilderment to me.

I understand I am debating with guildmasters here, but I have reamed to many chambers by hand, even for high-presicion rigs, to be convinced by just statements.I have never wallered out a chamber, they are just as tight as when I ream them in the lathe.

In this case, were we open up a 45-70 to 45-120,
one would have to be incredibly clumsy to make the chamber "outwallered"!

Compared to your engraving, Kerr, it is like sitting in the sofa, watching people taking a walk in the park - on TV.