So I've only done around a dozen barrels so far, all with Clymer reamers. Years ago I bought five .284 tapered barrel blanks from Sarco which I'm now getting around to. Everyone seems to praise Manson reamers, so I bought one (7x57) off Brownell's. Drilled and tapered and right off the bat got a funny sort of chatter; a chatter that seemed to make the reamer go back and forth in the X axis. My set-up is pretty rudimentary, I use a polished morse chuck taper in the tailstock as a pusher, holding the reamer with a short 3/8" end wrench. I tried everything I found on his site (fantastic explanation of this situation) as remedies. Nothing straightened it out and I left it short hoping turning the final amount by hand would do the trick - NOPE. Test fired and sure enough there were by feel, detectable flats completely around the cartridge. Now, when I did the final cuts I noticed that only three of the flutes at the shoulder were cutting; first one a leettle bit then the second more and the third the most. All one after the other. The three after had nothing on them. I then whacked off the tenon for to give it another go. I couldn't remove all the chamber as the barrel wouldn't allow that as it was pre-tapered. This time (as per one of his recommendations) I stuck the reamer more or less solid in the tailstock, figuring, what the hell. I tried speeds of 40, 50, 60 all the way to 120. Around 50 seemed best but I still had chatter (if that's what it is because you can't really hear it) but you can still see flats as it rotates slowly in the lights but are more shallow (I think). The chamber (as the other was) is light as an iced sphincter.

Is it me or the reamer? I've always found it hard to believe that a precision tool can be fluky. I ALWAYS think it's me.

It's you. Sorry to have to say that. It definitely is NOT NOT NOT the Manson Reamers. Dave makes the best reamers, and is a nice guy too. I have several of them.
I wish you had asked me before you started this project.
1: Those cheap sarco barrels are not properly stress relieved and are left overs from some unknown place; they are not from a quality barrel making firm that knows how to make barrels. That is why they cost $50. And Yes, I got a couple just to try; they are now pry bars.
2: You can't possibly chamber a barrel unless the reamer is controlled somehow; it can't just float on its own. Even the floating reamer holders are more firm than that.
3: Once you get chatter marks, they are hard to remove. But unless you have control over the reamer, it will chatter again. I only had it happen once and that was from a way too small pilot.
I hold the reamers with vise grips, with the tail stock center in it. I also have a floating holder. I never get chatter.
4: Your barrel setup has to be good; held at both ends and preferably checked for runout at both ends. There are several ways to do that. I don't know if you are holding it in a chuck or steady rest; in any case, it has to be dialed in and held tightly. PM me if you want to know more.
So, I recommend that you get some quality barrels (I use only Douglas; the best and by far the most responsive to my custom orders), and get control over your reamer, if it is still sharp.

What he said

It could be the reamer but I doubt it. Get some plain old wax paper and wrap around the reamer, a couple times around the reamer, insert in chamber and cut. DO this two times or more until the chatter is gone. You won't believe it until you try it

Did you check if the pilot is a reasonably close fit to the bore?

Pilot don't matter, I've seen a number of good chambering guys that don't bother with them

quote:

Originally posted by Jim Kobe:
Pilot don't matter, I've seen a number of good chambering guys that don't bother with them

With respect to my friend & colleague Mr. Kobe, I could not disagree stronger. Reamers have pilots for a reason; they align the body of the reamer with the bore. Were it not so, every reamer manufacturer on God's green earth would not make piloted reamers and interchangeable bushings in 0.0002" increments.

About 30 years ago when starting out, I bought the cheapest reamers available, Clymer solid pilot jobs. They cut wonderfully multi-faceted chambers because the solid pilots were .002-.003" smaller than the bore. I tried the old waxed paper trick but did not start getting repeatedly excellent chambers until I started buying reamers with interchangeable pilot bushings from JGS and PTG. I take care to fit a pilot bushing to every individual barrel I chamber. The result is lovely, round, chatter-free chambers and throats free of tool marks. Of course, it goes without saying that experience & knowing how to ream a chamber goes a long way to happiness. But for me, a properly sized pilot bushing is essential to ensuring a good, concentric chamber, and yes, I measure the concentricity of my chambers with a DTI not just by eyeball.

Roger

There’s more than one way to skin a cat, and Kobe is right. With a properly dialed in barrel, a pre-drill, and pre-bore, no pilot is needed. When preboring, a taper the same as the reamer will insure the reamer follows the hole. On small chambers, like 6ppc, and 30br, I make one pass with the reamer, usually the last .030”-.040”. I also set the headspace after the chamber has been completed. I consider any runout over .0003” less than desirable, measured with a test indicator in the throat, neck, and base.

I don't think it's me. The wax paper didn't do anything that I could tell. Test fire and the case was the same as the last. You can't really tell by looking, must spin between fingers. I mean, the thing can be shot and I will take it to the range for kicks.

I then took a 1" round of 6061 T6 and tried again. Before anyone has anything to say about that, it's worked wonderfully to make dummy stub barrels for using on magazine geometry when changing calibers that action wasn't designed for. I did one two weeks ago in .308 - beautiful! This time I spent even more time setting up than I normally do for such as they aren't gonna shoot anything. My letter drill J was a nice snug fit, I mean tight. I did no pre-bore or anything just a straight hole. Everything just ducks until I hit the shoulder. About 3/4 inch past was all I needed to see. Too late. I just can't reconcile this over my past, though admittedly limited, experiences. When doing the boring with a hand involved there is this slight bump, bump, bump that is metronomic with the speed.

Off topic: I discovered that my Japanese pocket knife cuts the most beautiful little radius (hand held) at the breech end that I've ever done. No set up!

What kind of lathe are you using and how are you holding the barrel?

How did you pre bore the barrel? (size, depth, type of tool)

Yes, good questions; I was going to say come over and Ill show you how to do it, but I see you might be 2000 miles away. I thread and chamber at least one barrel a week. In many different calibers. I still think the steel in those sarco barrels has hard spots in them. And your just pushing the reamer in I also don't like. Not that I know anything; just ideas. But blaming the reamer? None of my Manson reamers chatter.

Clymer reamers do have a tendency to chatter and a close fitting pilot can help. I believe the main reason they, or any other reamer, tends to chatter is, they are ground with the face of the cutting edges on center and not staggered. In addition, they often have just a little too much clearance.
When I have made a six flute reamer, I cut the flutes as follows:
1. On center
2. .002" ahead
3. .004" ahead
4. .006" ahead
5. .004" ahead
6. .002" ahead
That's what I was taught and it seems to work.
One fellow I knew cured one of his reamers by simply removing one cutting edge so it became a five flute reamer with one real wide flute. While it seemed to work just fine, I've not chosen to try it on one of my reamers. Regards, Bill

He is not using a Clymer reamer; he has a Manson.
I still do not understand all the chatter talk; I never get it.

My lathe is a Sheldon EXL-46B made in 1963 for the USAF. I got it surplus from the City who got it 25 years ago from the Air Force. The City machinist (retired and only came in when they needed him) has been one for fifty years and he said "it's a good lathe". I converted it to 1HP AC/DC motor with a Penta KB drive. It came with a 4-jaw Cushman, 3-jaw Sheldon, taper attachment, two face plates and a steady that needs fingers I can't find. The primary tool holder is a 4 position Logan modified to fit. I chamber/thread at the 4-jaw, I made a spider. I make my own pin gauges that JUST fit out of aluminum. I don't have any deep-reach indicators. All I want out these of things is a 'minute-of-moose' accuracy. This Sheldon has a 1-3/8" bore and a D1-3 spindle. The fun part is I bid $577.12 just for laughs as I already had a lathe. I was the only bidder. I could have dropped all the first numbers to the left of decimal and got it.

I really appreciate the input you all have given but this is what I'm going to do: Contact them and see if I can send it to be checked. If I'm wrong I'll certainly let everyone know.

I flipped the billet, took the best fit drill and rebored with, of course, the bit wobling around. All of this aluminum stuff I did in the 3-jaw. I then took a Clymer .308 reamer and had a go. Pushing by tailstock and wrench around the same depth, the reamer flopping around about .004". In other words, I did about everything wrong that I could think of. Here are pictures of both results. To my simple mind something is pretty obvious:

I've had four or five reamers which had a real tendency to chatter; all were Clymers. In this particular case, I think the holding and driving set up is the issue; or is at least contributory. Regards, Bill.

Stop pushing it with your tailstock flat; that is not a good thing.

Well, if someone could give me a good reason WHY these two results are completely different I'm all ears.

Given the extra information gleaned by your testing, I would say the reamer is the issue. Regards, Bill.

Everyone makes a bad product from time to time. Myself included.

Without seeing the reamer, and not knowing what you have available to inspect, it would be nearly impossible to discuss over an Internet forum and determine the issue.

Nathaniel, I don't really have anything with which to check it. I wrote to Mr. Manson and will wait to hear from him but for now, I'm done and I'm not going to go on another rabbit chase.

A couple of years ago I bought a Manson reamer. I don't remember what case. Any way the dam thing chattered bad & every trick in the book would not stop it. I called Manson & he was very good about it. I sent it back to him & he reground it. Said he took a test cut with it. Worked fine after the regrind. Shit happens but how the company fixes the problem is what counts. Manson will take care of you. I now ask the reamer makers to take a test cut with them.

This is what I did: over two weeks ago I called Mr. Manson, didn't get a pick up and wasn't gonna play phone tag so that same day I sent him an email explaining it all with a link to this thread as I didn't want to duplicate everything. After a week with no reply (nothing in the spam folder), I called Brownell's and instantly got a return label. Of course, I ordered a Clymer reamer afterwards. I got it today and the first thing I did was to run it into the Aluminum dummy - cleaned it right up. Then, I dismounted the barrel and gave the reamer a go - by hand. Very interesting! It did not at first feel good at all what with intermittent stops and goes, like wowzer. Slowly I was able to get it to smooth out and after around .060 at least the first third of the chamber cleaned with the remainder still showing signs of flats (or points?) but very much better. So I've lost a thread and ain't gonna do no more as I've already removed the tenon once. I'll buckle it up again and test to see if it's at least salvaged. I do not think that it could be truly cleaned without making it ugly Remington like with what's left if I cut the tenon off again. Or, I might get a 7mm-08 reamer, which would leave more barrel.

Here's my completely unprofessional opinion: the Manson was cutting more on one side, as I explained earlier, whereas the Clymer cut around.

Anyway, I don't think it was me. Others will disagree. Nothing from me here against Mr. Manson, at all. He's busy, so am I and probably less time was wasted with back and forth.

To bring this to an end, I test fired the barrel (mounted on a '94 Brazilian) and there were still vestigial remains of bumps aft on the fired cartridge but nothing like before where the whole of it was bumpy from stem to stern. I'll see if it was worth the effort at the range.

I then queued up another of these Saco barrels and had a fine (? the proof will be in the shooting) result.

Case closed, at least for me.