lines or ridges in chamber

K

kman

Guest
my barrell already threaded and head spaced but the chamber has lines from the back of chamber all the way to the first shoulder u can feel with finger ,its a 338 laupa mag,the reamer is new ,i tried speading up and slowing down the chuck speed and feed rate of reamer ,with tail stock pushing in ,but nothing works ,has anyone seen this and what do you guys sujest to fix

thanks for any help
in advance
 
From your description this sounds like "chatter" unless I'm picturing it wrong.... ????

You will get some more experienced answers from other posters who do this stuff for a living but IN MY LIMITED EXPERIENCE this has to do with reamer bushing fit. FOR ME I have had to bite the bullet and get the full spread of bushings so's I can find a tight fit..... I have 13 Dave Kiff .338 bushings!!!

I've had good luck using Do-Drill for lubricant and I predrill and prebore.... but I've only done 4 of the .338 Lapuas. Mine are Improved though, which in my experience makes them harder to do, and they've gone very well. Very smooth. The first time I wrapped my fingers up and waited for the bite I was worried! They pull a little but I've got no problem reaming them hand-held. And all my chambers interchange. I even cut one whole chamber off and screwed a pipe on for a fireform barrel...just to make brass for the others.

I've never had to try the "waxed paper trick" cross my fingers!

al
 
Couple of questions:

Are they lines, like a scribe line, or ridges?

If it's a line, like you let go of the reamer and let it spin at the end of the cut (which I always do), you might (I haven't but I can see how it could happen) get faint lines from where the reamer cutting edges stopped that you can see, and feel, barely. If that's what they are they should polish right out.

If they are ridges, almost like long but very shallow splines, that's chatter. I'll leave it to others to discuss how to deal with chatter in a finished chamber, if that's possible, because I've not been there done that. I have done the waxed paper trick to stop chatter early in the chambering process, and it worked, but I've not had it when the chamber was almost finished.

Do you have a camera with good macro capability and some bright lighting so that you can get a good close up picture of this phenomena near the breech end of the chamber?

Fitch
 
chamber lines

the polishing trick will not work these are very pronounced lines im gonna order a set of bushings and cut chamber off and re- due chamber i dont have a camra to send pictures if you guys can come up with any thing different please share,


thanks for any advice
 
I had this happen with a new 7mm mag reamer .I tried the same things you did . The pilot fit good . I needed to get the barrel done so I had a reamer sent from Dave KIff it work fine. the other reamer was a manson reamer I have used manson be for and thay are great reamers He took the reamer back and said it was a sharping problem. He treated me great JOR
 
If it is chatter marks

take a piece of wax paper and put it over your reamer. Ream another .02 or so and see what it looks like. If it looks like it's cleaning it up, ream till it looks good. I shouldn't take much more than 50 thou unless the chamber was really bad.

Richard
 
I think the big problem is that we don't really know what's happening without a good photo. I think without photos we are pissing in the wind. We don't know if it is chatter or swarf[chips] cutting the chamber wall.
Butch
 
lines in the chamber

ok lines are gone ,i turned spindle by hand really slow and had friend turn hand wheel on tail stock ,i went in 60 th and everything cleaned up really nice

thanks for all the help
 
Rings in chambers are generally caused by not clearing chips out of the reamer. Also cool tool is to thin for my liking I've had the tightest chambers with thick cutting fluid like union butterfield or that high $ stuff clymer sells. Also touch up your reamer with a fine stone @ the correct angles, set back barrel .250 and start slow on spindle rpm an feed rate remove reamer and clean chips when they start exiting bbl once the finish is smooth speed up spindle speed slowly but keep reamer very clean and feed it slooow!!!!
 
kman said:
ok lines are gone ,i turned spindle by hand really slow and had friend turn hand wheel on tail stock ,i went in 60 th and everything cleaned up really nice

thanks for all the help
Click to expand...

Sounds like a machine tool design/alignment problem to me...or a reamer with too much secondary clearance. But like Butch said, no photos, no better analysis.

But if you got it fixed, just recheck lathe spindle bearing adjustment and reamer grind before doing another. If you did get chatter by reaming too high reaming RPM, it is really difficult to get it out.

Many of these new WalMart quality Chi-Com lathes do not have enough structural integrity in the headstock casting or bearing quality on the spindle bearings to do top quality gun work.
 
JerrySharrett said:
Sounds like a machine tool design/alignment problem to me...or a reamer with too much secondary clearance. But like Butch said, no photos, no better analysis.

But if you got it fixed, just recheck lathe spindle bearing adjustment and reamer grind before doing another. If you did get chatter by reaming too high reaming RPM, it is really difficult to get it out.

Many of these new WalMart quality Chi-Com lathes do not have enough structural integrity in the headstock casting or bearing quality on the spindle bearings to do top quality gun work.
Click to expand...

AMEN to that statement...you are right on the money Jerry...!
 
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