Home Forums Hunting & Shooting Gunsmithing Chambering help required please

Hi
Im having a go at rebarrelling my rem 700, got the barrel set up through the headstock with spider each end
Using a bald eagle reamer holder and hss finish reamer with interchangeable pilot in 30-06
Using a flushing set up running the normal cutting oil but it is a little low on pressure so ive been backing out every 60-80 thou to let the chips clear
Running at 180 rpm
Have developed a bit of reamer chatter with about 1/2” left to cut, tried feeding the reamer in faster to cut through it but the chatter has remained
Does anyone have any advice ? Any help would be much appreciated. Should I try faster rpm Or maybe slower?
Thanks
B

fill the reamer flutes with chalk, that will stop the chatter, go slow. only had one barrel chatter on me, a Shilen select match

Another trick is to wrap the reamer with waxed paper, go slow when you are putting the reamer back into the chamber.

Something is not right with the setup. What make reamer? Screw retainer as in PTG and JGS reamers, or tiny snap ring retainer as in Clymer and Manson?

Your pilot bushing may be too small. I have sets in 0.0002" increments for all bore sizes. You should just be able to push the pilot into the bore. I have rods made up with a retaining screw to hold the bushings. I use this rod to hold a bushing when I try a bushing for fit in the bore. Keep trying until I have a snug fitting pilot bushing. This bushing then goes on the reamer. Just for kicks I made long rods so I may push bushings all the way through the barrel. Surprise!!! Even those premium barrels we pay a lot of money for are not consistent in bore diameter over the total length.

With the Bald Eagle holder, the reamer will oscillate due to your arm muscles trying to hold the reamer stationary. I call it the "rubber band effect" as your muscles act like a rubber band rebounding. Sometimes you cannot easily detect this. The reamer sort of flutters in the chamber. Add a too small pilot busing and you have disaster.

I use PTG reamers with the screw to hold the bushing. And I notch the screw at the reamer flutes, this allows a lot more coolant flow. The flutes on PTG reamers extend under the bushing and out to the end of the reamer.

Note the notches in the screw line up with the flutes: Other reamer makers do not extend the flutes under the bushing and out to the end. Combined with that silly snap ring you have restricted coolant flow.



And I use a precision industrial floating holder, it will not chatter.

Top, the precision industrial holder. Middle, the Clymer holder. Bottom, the Bald Eagle holder. I quit using the Clymer and the Bald Eagle holder many years ago.



My setup below. I run 30-06 and larger reamers at 300 RPM. Smaller reamers at 470 RPM. If you run the reamer too slow it will scrape instead of really cutting. Causing chatter. A dull reamer will also cause chatter.



There are over 100 chamber reamers in this big Kennedy chest. And dozens of pilot bushings. And other chambering tools. I have chambered over 300 barrels in my lifetime. Only one chattered and had flutes in the chamber. This was before I figured out tight pilot bushings and a really high quality reamer holder.

Whose reamer? Clymer tends to want to chatter more than others. One of the most common culprits is an undersized pilot. If your pilot is correct, check the setup. The less rigid your setup, the more likely chatter is.

I've only had two barrels chatter. First was my mistake, I has chambering two different barrels in the same caliber but they had wildly different bore sizes. The first was the smaller so when I forgot to change the pilot, I got some chatter on the second barrel. It was at the start of the chambering process so I used a boring bar to eliminate the ridges, changed the pilot, and I was golden.

The other was harder to explain. I suspect the barrel had some areas of varying hardness. Reducing the speed, increasing feed a little and wrapping the reamer with a cleaning patch eliminated the chatter.

Thanks to all of you for your advice, its a manson reamer, i’ve used it before with no chatter but I will definitely check the pilot fit again tomorrow.
B

When you guys mention wrapping the reamer am I correct in assuming that it is just the body that gets wrapped and nothing on the shoulder?
Thanks
B

What is your pilot size now? Who is the barrel maker?

When I used a patch, I poked a hole in the middle like a poncho and pushed the reamer through. The patch ended up on the shoulder and body. I had to replace each time I removed to clear chips. On this particular barrel, I had to use the patch method to complete the entire chamber. Even though the original chatter cleared, if I left the patch off, it started to chatter again. It was a customer supplied barrel. From then on, I required the customer to either let me buy the barrel or they could have a barrel sent to be directly from the manufacturer or supplier. Bottom line, I had to be sure who the maker was.

Its a bergarra barrel and ive got a .3000 pilot on now
Am i right in thinking to use a 2” x 4” 30 cal patch?
Thanks
B

Have had the same scenario believe it was a 5R rifleing but could have been 5C as well? Do not remember. The patch will work , once you start you need to continue to the end.

Thanks
Do i just rub the reamer with a stick of chalk until the flutes are full?
B

Thanks for your reply
My next step up is 270 rpm do you think that speed will be ok with a hss reamer and stainless barrel?
B

My next step up is 270 rpm do you think that speed will be ok with a hss reamer and stainless barrel?


Yes you should be fine, I chamber at 280RPM with a flush system pumping 30-40PSI with dark sulfur cutting oil and a gallon of Automatic trans fluid mixed in.

Cabriolet: What make is your precision holder?

I had a Clymer, and sold it to someone else some years ago. I am now using a Bald Eagle with a straight shank that you stick in a tail stock chuck. Careful, and not too tight. I am not familiar with your precision holder, and would like to check one out.

Thanks again all of you that gave your advice, i managed to get the chamber cut with a good finish on it in the end today.
I checked again with the pilots and found that the bore had increased as i had cut in so i went up two pilot sizes to .3004”, I dropped the speed to 80rpm and gave it a try but the chatter remained.
Tried turning the reamer by hand whilst applying feed with the tail stock but still chatter.
Finally tried the patch on the reamer method, I put the reamer in and set a dial gauge on the tail stock so I would know when i was cutting the metal and then took the reamer out, poked a hole in the middle of a 1 1/2” square piece of patch, slid it over the pilot down onto the shoulder of the reamer and oiled it all up and fed it in for a cut of 0.010”. Took it all out , cleaned it up, new patch on and same cut again.
Cleaned up again and the chatter marks were gone🙂🙂
Carried on and cut the rest of the chamber 0.050” at a time with no patches and no chatter
Fantastic result , very pleased and really appreciative of all your advice
Thanks again
B

For info theres an article on Dave Mansons Site about chatter in chamber reamers

https://mansonreamers.files.wordpress.com/2015/06/chatter-i.pdf

B

Glad it worked out for you.

You can expect the same results with a piece of waxed paper.

and file chalk

And masking tape.