Need chambering expert

[DickE]

Reaming a 270 AI chamber in a Krieger bbl. PTG reamer. In just about all the way, reamer gets tight in chamber, hard to pull out, does not seem like it is cutting like it should. Bushing pilot fits fine. First chambering with this reamer. I have run a copper 4 gauge wire over the edge to see if it had a build up but did nothing. 1- Could reamer be not cut right, but does seem sharp? 2- Has the metal in chamber area be work hardening to compound the problem?
At my wits end as to why.

 

[Ksracer]

I've had several reamers that didn't like to cut freely on the case body portion. You might try scuffing the chamber walls with some course grit Emery to give the cutting edge a chance to break through the "glaze".

 

[liljoe]

I have a couple of reamers that cut exactly the same way.
They are from a manufacturer that I use to buy from.

Joe

 

[Tim Singleton]

Try changing to a slower rpm and more pressure on the pusher until it gets a bite

 

[gunsandgunsmithing]

I've seen it on different barrels with the same reamer, but not on others. There was a spell where it was fairly frequent that seems to have gone away. I'm convinced it's in the steel, as the same reamer, on the next barrel...no problems at all. While I can't offer a 100% solution, I do think reamer geometry could fix the issue...i.e...more relief angle, perhaps. JMHO, so it's worth what you paid for it.

Any chance this blank is maybe 3-4 years old or so?

 

[Rustytigwire]

Dress the cutting edges gently, carefully, with a stone.

 

[SBLH10]

4 or 5 years ago a friend of mine was chambering a 280 Ackey IMP. Bartlien barrel PTG reamer new first time in use. He got about half way, when ne called me on the phone and said reamer is stuck can't get out.
The next day or so he brought it over to me with the reamer out and said it now won't cut. I set it up and spent an hour indicating the barrel in and then drilled it. Chucked up the reamer in the tail stock traced the reamer with a .0001 indicator setting the compound to where the indicator read zero full length of body. Then taper bored the chamber to within .005 of chamber size then the finished the chamber with his reamer and it cut like it was butter. The finish chamber looked good and the rifle shot very well and it is now his most favorite hunting rifle. (Built on a custom action)

Chet

 

[rgc54]

Are you chambering thru the headstock?
If you are it could be off center??

 

[Rustystud]

What coolant/lubricant did you start out with? Did you work harden the barrel and dull the reamer. I also see a comon denominator in the reamer manifacture. I have never had a problem with JGS, Manson, or Clymer.

 

[carlsbad]

If your bushing was tight at the mouth of the barrel it could be too tight at the throat loacation. I always run mine in on a grizzly rod to make sure i have a good fit at the throat.

 

[accuracyman]

Carlsbad offers solid advice. If that doesn't work then the reamer may very well be the issue. I had one like that where the body would "rub" on the back side of the flutes because of insufficient relief. It made the reamer very difficult to insert and remove. Called up reamer manufacturer and sent it back. It came back fixed and worked great after that. Anyone can let a bad one get out every once in a while.

 

[jkohler]

What RPM was you running and how was you feeding the reamer as in was you dwelling in one spot and work Harding the steel. You could always take off the bushing and give it a try.

 

[Dusty Stevens]

Tight spot on the bushing i bet

 

[clowdis]

Every time this has happened to me a smaller bushing solved the problem. Carlsbad is correct, just because it fit in the end of the barrel doesn't mean it fits 2 inches into the bore.

 

[msalm]

Only time this has happened to me, and it has several times, was with longer (LA) chambers. My ‘theory’ is the bore drifts off from the path the reamer initially started out at. The pilot is trying to straighten things out but the reamer is binding. Sometimes a good heavy, short feed will cut enough that that things tend to free up enough to finish the chamber.

When doing this I just fed in pretty hard and I could feel the reamer take a heavier ‘bite’ and the tension holding the reamer would drop to normal. If this was a really long chamber, it may happen twice before getting to proper headspace depth.

 

[DickE]

1. Tried @ 60 rpm-no help(slowest speed)
2. Removed bushing- no help
3. Using Ridged dark heavy cutting fluid. high sulfur (buy it by the gallons)
4. Normally ream at 180 rpm. has shown to be best speed on my machine for pressure and cutting speed.
5. Will not touch(dress) cutting edge on brand new reamer. will be sending back to manufacturer to have it inspected.
6. Brand new Bartlien barrel. sorry for stating Krieger.
7. Did try scuffing chamber, did seem to help for a while.
8. Ream through the headstock. indicate with a mitutoyo .0001 indicator
9. Always back off reamer, let the lathe come to a complete stop, prior to reamer removal.
10. Switched cutting oil, Don't use it much but tried Mystic metal mover. seems to help the most, only a short ways to go, cleaning reamer and chamber every .030"

 

[DickE]

I know it is very hard to diagnose a problem without being there or physically seeing the problem. A lot of good possibilities listed here, and good suggestions. Over the years I have learned a lot from reading posts here. Don't reply to many, as there seems to be really good replies very fast, without me. I thank you gentlemen for your help. Will be sending the reamer back to have inspected. If there are more suggestions, or like circumstances please do not hesitate to further replies

 

[carlsbad]

Once you got stalled and quit moving forward, the tool has been rubbing on the surface and work hardening it. So you could now have a work hardened surface independent of whatever caused the original problem.

I will say I'm speculating. I've never seen that occur in a chamber but I've seen it on 300 series stainless steel frequently when trying to cut with a dull tool. --Jerry

 

[WayneShaw]

I've seen it on different barrels with the same reamer, but not on others. There was a spell where it was fairly frequent that seems to have gone away. I'm convinced it's in the steel, as the same reamer, on the next barrel...no problems at all. While I can't offer a 100% solution, I do think reamer geometry could fix the issue...i.e...more relief angle, perhaps. JMHO, so it's worth what you paid for it.

Any chance this blank is maybe 3-4 years old or so?

C'mon, it can't be the steel. Ask any barrel maker and they will tell you all their steel is made with the same spec...........

 

[DaveTooley]

I have never seen work hardening in 416.
Just an educated guess here. You leave the reamer in contact with the steel until the lathe stops. That can't be good on the cutting edge. How bad will vary reamer to reamer and manufacturer to manufacture. Some reamers, for lack of a better term, fit tight and want to stick. My experience with this manufacturer points to a problem with the reamer.