Reamer chatter.........

I have heard of the copper penny treatment before...just never used it since all of my reamers (PTG brand) never gave me any chatter...but when the replacement Manson reamer arrives I will probably wear out 50cents worth of pennies on it before wrapping it in some premium brand wax paper, and oiling that with some Rigid dark cutting oil, and sending prayer money to Oral Roberts University ;) all before trying to cut the rest of the chamber :)
 
eww1350 said:
I have heard of the copper penny treatment before...just never used it since all of my reamers (PTG brand) never gave me any chatter...but when the replacement Manson reamer arrives I will probably wear out 50cents worth of pennies on it before wrapping it in some premium brand wax paper, and oiling that with some Rigid dark cutting oil, and sending prayer money to Oral Roberts University ;) all before trying to cut the rest of the chamber :)
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You will need to get rid of that existing chatter before you proceed.

It looks like you are cutting the entire chamber with the reamer??
 
If the chatter is caught early on, it may be eliminated by filling the flutes with a heavy grease or with plasticene. The alternative is to wrap the reamer with cloth or paper toweling and cut through that.
The root cause of the chatter may be a pilot which is too loose but if the relief angles and margins are correct, the reamer should cut well with no support at the front. I once had a Clymer 7x57 reamer which was a chattering SOB. I fought with the darn thing with every use. Finally, out of desperation, I removed one cutting edge by simply grinding it away and that reamer never chattered again and cut a bunch of chambers until, offended by it's appearance, I replaced it.
Reamer flutes should be staggered and the cutting edges should be ahead of center. If not, the reamer may tend to dig in and chatter.
Sometimes feeding the reamer faster while turning the work slower will help to control a tendency to chatter. Regards, Bill
 
Bill Leeper said:
If the chatter is caught early on, it may be eliminated by filling the flutes with a heavy grease or with plasticene. The alternative is to wrap the reamer with cloth or paper toweling and cut through that.
The root cause of the chatter may be a pilot which is too loose but if the relief angles and margins are correct, the reamer should cut well with no support at the front. I once had a Clymer 7x57 reamer which was a chattering SOB. I fought with the darn thing with every use. Finally, out of desperation, I removed one cutting edge by simply grinding it away and that reamer never chattered again and cut a bunch of chambers until, offended by it's appearance, I replaced it.
Reamer flutes should be staggered and the cutting edges should be ahead of center. If not, the reamer may tend to dig in and chatter.
Sometimes feeding the reamer faster while turning the work slower will help to control a tendency to chatter. Regards, Bill
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Great information, Bill. Thanks!
 
I would have chucked up some stock and let that reamer cut a little first (same concept as the penny). Have you ever had a drill catch like that and chatter? it is common with a sharp drill and soft material, when cutting brass you actually have to break the cutting edge sometimes. New sharp reamers will often chatter until they cut a couple chambers. The only time I've ever had bad chatter though is with that same brand...and more than once.
 
Never had a problem with Mansons reamers, thats why he's my "go to" guy when I need another, or alterations, or sharpening. I've got over 45 finishing reamers in my tool box and 90% are Mansons. I have had problems with another popular makers tools, the one everyone recommends!
 
I want to make it clear that I do NOT blame the barrel maker or the reamer maker for the chatter problem...I have observed "chatter" 2 times in my experience...I think it is an anomoly that I cannot explain the root cause, and have not heard of a way to avoid it by inspecting at the tooling or workpiece...I use good sound lathe techniques that have worked reliably to produce a number of excellent competitive rifles...


Eddie in Texas
 
Eddie, I've had just a couple of reamers that chattered out of over a hundred reamers. One was a .280 Ackley and the other a .223. Sending them back, fixed both of them. The .280 Ackley was replaced, the .223 reground. I did have a little chatter problem with the Jet lathe that I used to have. Changing it over to a VFD drive and not using back gearing worked itself around the chatter in that lathe. Something in the spiral gear setup in the headstock was causing the chatter. Replacing the bearings with Tempkin bearings didn't make any difference. Chambering and threading on the high speed side worked with it. The VFD allowed chambering at 80 rpm or whatever the lower limit was set on the VFD. The threads were where I got most of the problem with chatter with it though.
 
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.
 
J. Valentine said:
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.
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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.
 
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.
 
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.
 
Sorry guys...it is a .204 Ruger (Manson solid pilot reamer ) into a Lilja .20 caliber barrel blank...reamer pilot measures .1995"
 
eww1350 said:
Sorry guys...it is a .204 Ruger (Manson solid pilot reamer ) into a Lilja .20 caliber barrel blank...reamer pilot measures .1995"
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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.
 
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
 
chamber chatter

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
 
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
 
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.
 
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