Reamer chatter.........

[J. Valentine]

I am not experienced enough with chambering to give any absolute advice only having done a few average quality jobs.
However as a novice in this area I might be able to think outside the square so to speak.
Not saying that this is the problem but this is what I would do to try and figure out what is going on.
I know you don't want to move the barrel but I think that barrel vibration is one area I would like to visit.
What if you moved the barrel further into the chuck as it looks a fair way out.
What if you removed that copper ring that might be allowing a single pivot point for the rest of the barrel to vibrate about it's length and replace it with copper shims that allow the full length contact of the chuck jaws and far more rigid hold .
You are going to bore it out anyway so setting it back up will not change that much.
What if you wrapped a sheet of lead around the middle of the barrel and taped it in place to change the mass and absorb any vibrations .
What if you made a wooden or plastic plug that went around the barrel in the middle and slid neatly into the spindle hole to absorb any vibrations.
What about a threaded sleeve to screw onto the barrel tenon and tighten it up some to change any harmonics.
This might be total crap but it is things I might try , just to see if it is not all the reamers fault.

[JerrySharrett]

I am not experienced enough with chambering to give any absolute advice only having done a few average quality jobs......
This might be total crap but it is things I might try , just to see if it is not all the reamers fault.

Chatter of this type, the face of a machined workpiece as opposed to chatter on its diameter, is most times caused by axial flexing of something. Axial vibration can usually be traced to either the lack of structrial integrity of the workpiece or the machines own headstock. i.e. when the headstocks bulkheads are poorly designed they flex, like the skin on a bass drum. Workpiece design, an extreme example woulld be facing a hubcap-but you get the idea, can cause chatter on the orkpiece face. But with the axial rigidity of a gun barrel the problem is not the barrel face flexing.

[flatlander]

Even with an Ackley-style reamer, I've never had the chatter at the shoulder as seen in the photos the OP put up with the original post. All the chatter I've experienced was body chatter, and if I let it go too long, I've had to use a boring bar to cut the chatter out on the un-finished chamber. IOW, I learned the hard way to take steps other than varying spindle speed and/or feed rate to stop the chatter ASAP. With any of the improved chambers - with reduced body taper - you don't have much room to work with if you let it go very long, and will wind up setting the bbl. back.

[M.D.Spencer]

What is the bore hole size in relationship to the pilot size of the reamer? If it's a couple thou different, you get chatter.

[eww1350]

Sorry guys...it is a .204 Ruger (Manson solid pilot reamer ) into a Lilja .20 caliber barrel blank...reamer pilot measures .1995"

[JerrySharrett]

Sorry guys...it is a .204 Ruger (Manson solid pilot reamer ) into a Lilja .20 caliber barrel blank...reamer pilot measures .1995"

So, what is the actual clearance?

I still think the chatter is axial not radial. A poor fitting reamer pilot would cause radial chatter not axial.

[eww1350]

Update...the replacement (Manson) reamer arrived today from Brownells...I was anxious to see if the new reamer would have the same "chatter" problem...I put the new reamer into the chamber which I had bored out the chatter left from the first reamer...as I fed the new reamer in slowly I could feel the chatter feedback thru the tailstock...I stopped and decided to try the wax paper and grease in the flutes...that did help, but still had a small amount of obvious chatter visible...at that point I decided the reamer was "too sharp" at the shoulder so I used my wire brush mounted on my 6" pedistal grinder which has .006" diameter stainless bristles..I ran the wire brush radially around the reamer only on the shoulder cutting edges just to remove the excess sharpness on the edges at the shoulder...and it worked..!!
the reamer cuts beautifully and has no signs of the chatter that appeared on the shoulder of the chamber...this reamer cuts like a hot knife thru butter...it is difficult to feel anything when feeding it in...and it cuts as smoothly at .050" depth as it does at .025" depth...I am very happy and can now breath a sigh of relief...

Eddie in Texas

[roscogin]

i saw a guy use cotton patches dumped in oil the problem was the reamer was too sharp,just place a couple of patches over pilot end and procede its worked the very first time

[alinwa]

Good fix Eddie! Thanks for that. I had a similar thing happen the first .22 barrel I bored for a sleeve.....gorgeous '06 gallery gun and I couldn't get that long ol' bit to keep from digging and uncoiling like Tigger's tail. Sweatin' the proverbial bullets this child was. Same fix, different day.

Good On Ya
al

[chino69]

I'm no machinist or gunsmith but have followed this thread with interest. When a reamer is too sharp, does it make sense to ream a few bores in scrap round stock in order to break the reamer in?

From what I've read it's possible to have a reamer that is too sharp; discounting flex in the lathe headstock and/or bearings. I know that gunsmiths treat their reamers with the utmost care to ensure they cut a good chamber.

[eww1350]

Chino...I agree with you that it seems strange to think a reamer is too sharp..but not being a tool and die maker it is hard to say if one can be too sharp...I have 12-15 reamers and never had one that didn't cut (stainless steel) on the first try just like it was designed to...but this .204 Ruger reamer started to chatter as soon as it was fed into the barrel...if I had not spent the time or effort to dial in the barrel...or had a second lathe I might have cut some scrap chambers with it, but how do you know and who has the time to "jack around" with a new reamer to make sure it cuts properly...I fully expect a new reamer to work just as it was designed on the very first chamber...I do not like the idea of dulling a reamer...we all try to keep our reamers in top condition to get the most out of our investments...now all that being said I wonder if this .204 Ruger (Manson) reamer would have worked perfectly in a Chromoly barrel...?

Another lesson in learned...

Eddie in Texas

[JerrySharrett]

Chino...I agree with you that it seems strange to think a reamer is too sharp..Another lesson in learned...

Eddie in Texas

A too sharp reamer, not unlike climb milling on a conventional milling machine that does not have backlash control, can grab and pull itself into the workpiece. 416 stainless, unlike chromemoly, has very free machining qualities.

Eddie, next time, on a new reamer, try what was mentioned above about rubbing a penny at 45 degrees along the cutting surfaces to instill some dullness. Using a wire brush like you mentioned can cause injury to you and damage the reamer.

[dialin' in]

I've used a BRASS brush on freshly sharpened cutting tools, but, never a stainless one. Applied just enough to remove any grinding 'burrs'.

[eww1350]

Jerry,..I use my wire wheel to clean threads on screws/bolts it is fairly soft and will not remove skin...in fact I use my bare hands to hold the screws and it is quite gentle...I would never use a stiff wheel...I use the same wire wheel to give a nice brushed finish to stainless actions or hard chromed actions it actually will give a brushed finish to aluminum...also I did work the new reamer over with a copper penny before I tried it and it did not help at all... I then went to the wax paper and heavy grease with better results but messy as heck and I wanted to get a remedy that would let me use the reamer with cutting oil only..that is why I went to the wire wheel...

[M.D.Spencer]

Their is no such thing as a Copper penny! Get some copper tube and only use it if you have a burr. Pennies are made of Zinc. Also how are you holding onto the reamer? Not with a cheep floating reamer holder....