Chambering and reamer chatter

[Rem700 shooter]

I’ve cut a few chambers now and they’ve all turned out excellent, this one gave me fits. 22-250 5R barrel. Had the chatter under control at one point and the it came back right at the end. The stuff you see on shoulder is just some scotch brite bits. How bad is this? Fired a few times just to look at brass, seemed to extract fine. Does it got any hope of grouping? I will also add that the case shoulders are relatively smooth, the light makes them look worse than they are

 

[Carl S]

You could polish it or set the barrel back a few thou.until it cleans up.shouldnt affect accuracy really.the target will tell you.

 

[boltfluter]

You might try cutting a few .001 with the reamer by hand. I bet it would clean right up. Just a thought.
Paul

 

[tobnpr]

Agreed, if the leade/concentricity looks good you could shoot it first- especially if it's already been removed from the setup.

I'm kinda OCD with this stuff even when it likely has no affect how it prints at the target; if it were still in the lathe I'd probably do the anti-chatter routine (wax paper or patches) and give it one more go.

 

[aussiedave]

The only chamber I have had chatter in was a 22-250 in an IBI 5r . Not sure why?

 

[JGSprecision]

The only chamber I have had chatter in was a 22-250 in an IBI 5r . Not sure why?

Small cal. , large shoulder, etc. Also many have swore 5R have given them fits.
Once it starts it has to be "cured".
The body of the reamer (tip of shoulder to shank) 's edge geometry seems to responsible for alot of chatter issues. An aggressive edge on the body can grab sideways as your chambering close to full depth so I prefer a body with less aggression. As a tool wears it develops cylindrical margin on the top of the flute and IME it cuts smoother with a slight margin on the body.

 

[LVLAaron]

wax paper is your friend

 

[Rem700 shooter]

Thanks guys. I should add, that the person I did this for ordered their own barrel blank at 16 1/4 without telling me first. I chamber through the head stock so I cut, crowned, and threaded then made a barrel extension first. I told him first that it probably was no dice because I like to take an inch off my crown end, however it didn’t appear to have any bell in it. So he kinda knew that this thing maybe a problem anyways, we will pin and weld a muzzle device if it doesn’t shoot, so I said all that to say that pushing this thing back wasn’t really an option. In hindsight I should have just continued to put a patch on every time I withdrew the reamer chatter or not if it’s gave me chatter problems at all. I machined a long time and have just started building rifles, I thought all these chatter problems were people that just didn’t know what they were doing with a reamer…… a piece of humble pie every once in a while does a man good.

 

[ridgeway]

Chatter can almost certainly rooted to the reamer if you are experienced and have your speeds and feeds in check. I had a problem with a reamer and at this point not afraid to say the MFG because I went the route of talking to them, sending it back for evaluation and was sent back with several band aid fixes(patch and wax paper) basically saying its on me. I inspected the reamer between centers on an optical comparator and found the entire reamer ran out almost a half thou from shank to pilot. Three of the body flutes ran out from a tenth to 4 tenths. Remaining three were dead nuts. They evaluated the reamer by plunging into a stub and told me it cut fine. I got it back and tried the wax paper bandaid and that created alot of tool pressure to settle down and bound up and pushed the reamer off center. Being that much run out, chatter is a problem as well as an oversized chamber. When i first got the darn thing, there was a wire edge on each primary land left from grinding. I was instructed to scrape it off with a copper penny. I should have inspected it then before I made a cut.

I ultimately sent the reamer in for a refund and nada. Guess since I used it...its mine. Bad thing is, I don't have it nor the refund! Not JGS, Not PTG, Not Clymer

So, the moral of the story is, check your reamers when they arrive. If you don't have that capability, find someone who can. This almost costed me a brand new barrel. Lost almost an inch off heavy end of a HV Brux!

 

[DShortt]

I personally stop short of finishing the chamber in the lathe and finish up the last little bit by hand.
But, I'm not a well-known so take that for what it's worth.

 

[DShortt]

well i dont know when this happened but Im not surprised from that company. i wont buy any reamers made by them. your story just strengthens my feelings about that. thanks

I think any company can make a mistake. What matters to me is the action, or inaction, or blame game when that mistake is presented.

 

[Rem700 shooter]

well i dont know when this happened but Im not surprised from that company. i wont buy any reamers made by them. your story just strengthens my feelings about that. thanks

We talking Manson? I assume so, that really surprises me, I have had nothing but positive interactions with them so far. Good to know though. I also don’t really have a great way to QC the dimensions either. It would make me feel better if you got a CMM report with them or something, I’d pay (a little) extra for it.

 

[tobnpr]

Every precision part that's machined has +/- tolerances,

I wonder what they are for reamers...

 

[JoeDuke]

Every precision part that's machined has +/- tolerances,

I wonder what they are for reamers...

Tolerances are listed on the prints.

 

[tobnpr]

Tolerances are listed on the prints.

Never looked at that before...
So, +.002 on diameter and +.015 on length for those I looked at.

Seems to me that tenths are irrelevant here.

 

[Edd]

Never looked at that before...
So, +.002 on diameter and +.015 on length for those I looked at.

Seems to me that tenths are irrelevant here.

What reamer print are you looking at? Mine show +.005" for length and +.0005" for diameter.

 

[ridgeway]

I don't see anything on the prints holding concentricity and/or run-out to any datums

 

[ELR LVR]

Every precision part that's machined has +/- tolerances,

I wonder what they are for reamers...

I have an email from Manson few years ago regarding this
I believe there "Factory Tolerance" +/- .001
or sometimes -.000/ +.002"
something like that
You can call out your tolerance specs
I did that once and wanted .0005" tolerance on some crucial specs for a reamer I was having them make
The tighter tolerances were quoted an extra charge of approx $110
They will do it for you, and not to fault them but in the process of asking for insurance of tight specs
I guess I forgot being a machinist myself
When sneaking up on tight tolerance, it takes more time for that type of accuracy.
Time = Money
Temp plays a role as well, as machines heat up bearings get looser
so they may know there own machine and have to run it in the morning which changes the schedule as well.
Which could be an inconvience they may also have to charge for.

 

[ridgeway]

My issue isn't pertaining to the diametric tolerance, but the end result becomes diametric. We all hold onto the shank. The reamers have two centers on each end. So, if any run out shows between the shank and any parts of the cutting flutes, then you can question any issues arise, IE chatter, over sized chambers, etc. On any decent machine, chuck your reamer on the shank, get that running true and check a few spots with a tenth interapid. You can see alot. I got a reamer to replace the one I sent back for a non existent refund and it checked out scary good. Go figure.

 

[DR_2297]

I got burnt for a Sporter profile blank earlier this year. The mfg replaced the reamer but I got the pleasure of eating the blank.

The one reamer I skipped cutting a test chamber with because I didn’t have a 6.5 mm drop handy (I now have 26” of drop). At least it was for me and not a customer.