Chamber problems

[brxlefty]

Chatter can be caused by a number of things, but a tight pilot isn't one of them. Potential cause include:
a. Loose bearings on the lathe.
b. Instability or flex in the holder/driver.
c. Improper (excessive) clearance angles on the reamer and
d. Improper reamer geometry.
Of these causes, I think (b) and (d) are the most common.
As Butch mentioned, wax paper can help (best used before chatter gets too bad). Wrapping the reamer in cloth, filling the flutes with Plasticene, or filling the flutes with a heavy grease, are also viable cures. WH

 

[Will Henry]

Whoever figured out the wax paper was pretty handy.

I first heard it from Max Clymer. Coincidentally, most of the reamers I've had which chattered badly were Clymer's. Had one, a 7mm Mag, which chattered with the slightest provocation. One day, I dropped the darn thing and broke a 1 inch section out of one edge. I just ground the damaged edge down so that it cut only at the neck and base. I figured I might as well try and finish the job so I did. It cut fine and never chattered again. I finally replaced it, but probably cut a dozen chambers with it before I did. WH

 

[DR_2297]

Had a 6XC reamer flute the chamber on its first use once. Was able to stick a patch over it, finish the last .200 and end up with a clean chamber. Sent the reamer back and it was reground and has been perfect since. Was told sometimes you may have a flute too close to center that can cause it. But whatever they did fixed it.

 

[AlNyhus]

The late Stan Ware would rub a pure copper penney down the edges of a new reamer before using it the first time to help with chatter. He had a small tin with what he called 'rubs' that dated back to when his father was a full time gunsmith.

 

[effendude]

The late Stan Ware would rub a pure copper penney down the edges of a new reamer before using it the first time to help with chatter. He had a small tin with what he called 'rubs' that dated back to when his father was a full time gunsmith.

Gosh I miss Stan the Man.....

 

[LVLAaron]

Gordy teaches that. He will give the reamer a rub with the penny towards the very end of the chamber. I use a piece of annealed c110 copper

 

[luckyshot52]

I’ve done a lot of chambers with many different reamers, some old and some brand new. Knock on wood no chatter yet. I drill and bore to about 0.010 per side. And then bore the first 1/8-1/4 to size of front of reamer. This gets reamer started straight. When reaming of any type the reamers are made to remove minimal stock. Read up on basic reaming.

 

[rem40xb1]

Setting it up straight is no small task.

I ran it in with a patch after removing the chatter with a boring bar and that worked

 

[boltfluter]

I’ve done a lot of chambers with many different reamers, some old and some brand new. Knock on wood no chatter yet. I drill and bore to about 0.010 per side. And then bore the first 1/8-1/4 to size of front of reamer. This gets reamer started straight. When reaming of any type the reamers are made to remove minimal stock. Read up on basic reaming.

In my minimal experience chambering barrels, this is my approach as well. Reamers, by design, are intended to finish the last few thousandths of a chamber and work great for this. They are not intended to drill a hole, or chamber, if you will. Years ago, when working in the machine shop, if we had a hole that had to be on size within .001 or so we always drilled or bored the hole within .001 to .002 of finish diameter and then ran the reamer in. Worked every time! Many combinations of hole size and reaming were tried before we came up with this combination, and most failed miserably. The combination mentioned above, .001 to .002 left to ream worked most every time. Just something to think about. Happy reaming!
Paul