How do you center the bore in the steadyrest before chambering?

I useally center the barrel on the pivot and take a cut on the outside of the barrel and then put it in the steadyrest for the chambering. It�s hard to get the bore and the outside perfectly lined up and I have started to use snug fitting pilots in the bore to get everything perfect.

It would be interesting to hear what metod you guys use to get the chamber perfectly lined up.

My Colechester lathe is a bit to big to put a barrel thru the spindle. A 22" barrel will not reatch thru the spindle to be lined up in the muzzle.

Stefan.

I have a 16" South bend and I understand why you would ask. First, I re-center the barrel. I use a removable pilioted centing tool to get the centers in line with the barrels axis. After that, I put the barrel beteewn centers. I check, down the lenght of the tennon. If it's close I'll make a lite cut, just breaking the surface. Only then, will I know, if my Tailstock is in line. When I am satisfied, I leave the barrel beteewn centers. Then move the steadyrest into position. I then have a good surface, that is not only staight but true to the centerline of the bore. Plus, it is concentric. After the rest is in place and the supports are finger snug against the barrel tennon. I place a indicator on the ways and the needle against the barrel. generally on the top. One on the side if you have two. I then move the live or deadcenter away and note any changes.I snug the adjustments a little more and Add way oil to the rest. Put your lathe into neutral and rotate the barrel. If the indicator needle doesn't move. She is good to go. Use the lowest speed and time is not something to concern yourself with, Reamers cost money Clean the chipps as often as you think you should ( use a good cutting oil).I use a Tap wrench and the ram from the tailstock to drive the reamer. Also, one small but important thing. Make sure the wrench can, if you let it go, swing 360 degrees, Between the barrel and center. If the reamer binds you can feel it and nothing bad happins. fun If you need reamers just call Dave Manson at dave Manson precision www.mansonreamers.com Have fun Tell dave I said you should call, for further questons. type you later M.D.Spencer.

[This message has been edited by Sparticus (edited 02-15-2002).]

Thx for your input Sparticus!

Stefan.

Any time. Sparticus the "Geek"

Stefan: After you're sure your tailstock is centered. With a large machine such as yours, I would chamber using a 4-jaw. Use masking tape to make a tape bushing around the muzzle end of the barrel that fits tightly in the bore. Use thin aluminum shims to keep from marking the barrel shank in the 4-jaw(about 4 wraps of an aluminum can works well). Then use a dial indicator to get your center off the inside of the bore, instead of the shank.

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JD

JD.

My spindle dia. is 2,5" so I�ll be the best customer at the "tape shop".

Seriously.

I have been thinking of doing some type of centering device to put inside the spindle axle but it seems like there will be lots of work involved and I�m not sertain that it�s going to be a perfect solution.

I use a indicator to check if the bore are out of line when using the steady rest. I feel that the steadyrest is a good solution if it�s possible to get the bore perfectly centered on the live center and take a light cut on the outside.

Interesting to hear other peoples id�as and metods!

Thx JD!

My grammar and spellig is bad enough before I get into tecnical stuff Hope you put up with it.

Stefan.

Stefan,
There are a few problems that may exist with a new barrel that will make it more difficult to center in the steady..
First the existing "center" as provided by the barrel maker may be eccentric to the bore.
The barrel shank may not be paralell or concentric.
Barrel may not be straight.
Shilen barrels, for instance, are ground as a final step. During this grinding the centers are somtimes damaged and the barrel shank is often out of round. So this is what I generally do when using one of these.
1. Hold barrel in three jaw chuck and support on center and take a light cut on the shank.
2. Switch to 4jaw and cut about 1/2 inch off breech end. Dial in the bore and recut center with piloted reamer.
3. Switch to faceplate and center to cut threads and take another light cut on shank if necessary.
4. Set up 4jaw and steady to chamber.
I prefer to crown in the headstock but if I want to do it in thesteady I will put a collar on the barrel and turn it while the barrel is between centers.
I can and have chambered both in the headstock and in the steady and prefer to work in the steady. Especially if the machine I am working with is worn or misaligned vertically. Regards, Bill

Stefan: Your English is great; no worries. My personal machine has slightly less than a 1" bore, so most of my work is between centers. I suggested the tape bushing for larger machines because I don't use a large one very often.

My experience with barrels is that the bore is usually not centered, and sometimes they're way off. You can't use the barrel's full potential with a chamber that's not square with the bore. That's why I always center off the bore, not the shank. By the way I'm an amateur at this, but I like accuracy.

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JD

[This message has been edited by JD (edited 02-17-2002).]