I need help. I'm still a newbie. How do I make sure that the Reamer is aligned correctly with the bore? On my lathe the tail stock is slighty off center in order to get it to turn true on a test bar. Presumably this is due to wear on the ways near the headstock. But I can see that if I simply chuck the reamer in it will be off center in relation to the bore.

Thanks,

Mike

First of all I'm not going to claim this is the only way to do this. It is the way I was taught and it works for me. As soon as I post this somebody will tell me I'm doing it all wrong, and tell me what a stupid SOB I am, but my chambers come out straight. I stretch the barrel all the way out in the lathe and run the live center in the breech end of the barrel. The I set the steady rest on the shank. I've equipped my steady rest with roller bearings and I adjust it with the machine turning. When the steady rest isproperly set up, I move the tail stock back and put the reamer in a tap wrench and use the live center to push the reamer into the work. Because the breech of the barrel and the reamer were both centered using the live center, your chamber has to be straight. There are other methods but I've always got good results with this one.

I'm sorry, something sounds awfully strange here and I'm only trying to help you.If you can get your Lathe to turn a test bar on 60 degree centers) true with no taper ( hopefully it's about 18 inches long), then why do you believe your centers are out of linear alignment even if you have had to set the tailstock over slightly? You should have corrected this in all dimensions. The most important thing about reaming straight is that there is a complete linear allignment of the centers( up down and sideways). I'd make sure your lathe was properly leveled first. Slight misallignment can be corrected using a piloted reamer with a floating reamer holder. If all of the above is true, you should ream a concentric chamber.-Rob

Migra,

Thanks. That's how I was figuring on doing it but wanted to be sure about alignment. I was actually think of using a floating reamer holder. But same general idea.

Rob,

I appreciate the help so no offense taken. I checked the lathe to see if it was level last night and guess what, it's not. I'm having a heck of a time trying. After I get it level, assuming I do, I'll try the test bar again.

The reason I suspected something was wrong is that even though I got both ends of the test bar the same diameter when I run the tailstock up to the headstock the center points are off. This had me worried that if I was to chuck a barrel muzzle first and use a steady rest on the breech end that I would be chambering off center. Don't worry, I'm not ready to try chambering yet. I still feel like I need some more experience with the lathe. I just want to be sure that I get everything set up properly.

Here's another newbie question: When chambering using the steady rest should I use a three jaw chuck or should I use a drive plate and dog? I was figuring on using the chuck.

Thanks,

Mike

You are listening, and not taking offense, which is much appreciated. All too often we get folks here who have but a smattering of knowledge and don't want to hear the truth. Some of them claim to actually be machinists of long standing which is a shame or debatable depending on your outlook.
From your post, your Lathe is not level and you first need to get it absolutely level. It also sounds like a light machine which will compound your problems. When you do get it level, I suspect the misallignment will disappear. You might order some lathe allignment buttons from Brownells which may help you adjust for better allignment. What Lathe are you using?
Turn a test bar about 18 inches long and test for taper. How much do you have/ft? You should hold within .001 all the way. If not lets figure out why, but the test bar tells all.
I suggest you use a known good three jaw chuck or better yet a collet chuck with less than .0005 runout and a center rest for your chambering. A properly piloted reamer like a drill will follow the path of least resistance i.e. the bore if given half a chance. It sounds like you will need a good floating reamer holder ( I use ones made by JGS) and use a properly piloted reamer. Ream no more than .050 per pass and clean the chamber and reamer with compressed air and an acetone swab each pass. Depending on what chamber you are cutting, use a rougher first then a finisher. The best way to tell if you have cut a truly concentric chamber is to do a cerrosafe cast and take carefull measurements.
Don't worry you will do fine, you are already asking the right questions and we will sort out the problem in short order. Here is to a mirror chamber on the first try.-Rob

Hay z1r, use a four jaw and indicate the barrel in. Second get Steve Acker's video from Brownells. He does a vary methodical method to rebarreling. Call Brownells, ask for that video. Sometimes it's easier to have a visual as you go. He give's the in's and out's without the usual B-llsh-t.(I just don't like someone's opinion on why he doesn't like something) He's just is vary straight forward.

[This message has been edited by Sparticus (edited 03-22-2002).]

Rob,

I got the lathe level and it seems to be working better. I didn't have time yet to cut another test bar but will let you know how things work out when I do.

I have an old south bend 13" on a 5 foot bed. It will turn a piece about 28" between centers. Where can I find more info about the JGS floating reamer holder? I knew Clymer offered one.

Thanks again for the help.

Sparticus,

Thanks for the tip on the video I'll have to look into it. I've read at least six diiferent references ob chambering but like they say a moving picture is worth a thousand still shots or something like that.

-Mike

-Mike

Way to go! The Clymer thing is a piece of Junk. Don't use it! Call JGS and order one of their floating reamer holders. Dave Manson also sells them I believe. You will get to know these people intimately if you start doing alot of chambers.
Your old Southbend sounds like a nice machine asuming its not made up from parts. However, these old Southbends have often been badly abused by people who don't have a clue how to run a Lathe. Call Dave at Meridian Machinery,www.Mermac.com for parts/advise if you need them. He's not a machinist but knows Southbend equipment and can help alot.I know what I'm talking about as I rebuilt a much abused Heavy 10 a few years ago.
Turn your 18 inch minimum test bar between centers and measure how much taper you have from headstock to tailstock. Adjust your tailstock set-over to minimize this taper. let us know what your results are. On older Southbends that have been abused it is quite possible that the headstock is out of allignment or that your headstock bearings are out.-Rob

Hi All. This is more to the question of the reamer holder. I used a Clymer for years and had some problems along the way, mostly chatter. Got the JGS holder and it is one GREAT piece of workmanship. Recommend Highly!! Also, make up a thru-barrel oiler. Greatly increases reamer life and chamber quality.Pays for itself in the long run in reamer sharpening. Greg Tannel sells a good one or make one yourself.Aloha, Mark[in Ore]

Dave Manson does make a reamer holder. You can purchase it from him or Brownells. Speed is a criticle thing, when chatter is a problem. Slow as you can go. I have a South Bend 16" I love it.

Go to www.benchrest.com and then click on "gunsmiths" on the left and click on Mike Bryant for a good explanation,