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Chill Wills
09-14-2013, 01:44 AM
What is you take on floating reamer holders and the varies designs Vs just using the ridged tail-stock?
Any experience? Does using the floating reamer holders risk wallowing out the back end of the chamber?
Are there times to use them?

Thanks! Chill Wills

Love Life
09-14-2013, 10:23 AM
Ask GoodSteel. I learned quite a bit about it from him.

B R Shooter
09-15-2013, 06:24 AM
I don't believe in them under normal circumstances. If your lathe isn't worn out, you can adjust your tail stock into alignment with the headstock, drive the reamer in with a dead center, and you will ream true to size chambers. I chamber through the headstock too, never use a steady unless there is no other way.

It always makes me wonder why people are so quick to go against the first principal in turning metal, and that is rigidity.

The other alternative to a floater is what's called a "pusher", which is a tool which is chucked in the tail stock, and it has a flat face that pushes the back end of the reamer. Many use this instead of a floater.

The bottom line is, there are as many opinions on this as the are about what is the best barrel. The end result is what counts.

leftiye
09-15-2013, 08:18 AM
Unless your setup is on the center of the bore (somewhat of a problem with rechambers, military barrels, etc.) you can bust a reamer if you don't use a floater. Amazing how off center some of the best barrels are. Yeah, you could set up on the bore, with center in back of reamer, slight pressure, turn lathe by hand, clean, repeat a bunch of times, etc., etc..

B R Shooter
09-15-2013, 10:15 AM
How do you get "off center" of the bore if you indicate in the barrel? Unless of course you are using a steady rest, where you are reliant upon the OD. That will never make a good chamber. If you turn the OD concentric to the bore, then you'll be closer. But if for some reason you have a barrel where the bore is not close to the OD (which I have one right now, a Remington) the only way to set it up is using a set-true or 4jaw.

Floater or not, you can't ream a chamber if the bore is not indicated in.

eck0313
09-16-2013, 01:08 AM
Well, I've seen some barrels (cut rifled) where the base of the grooves, and the tops of the lands weren't exactly in agreement as to the axis of the bore. A 50 millionths dial indicator can be a real eye-opener.

akajun
09-16-2013, 10:17 PM
Its easy to cut a chamber oversize or offcenter if you rigidly hold the reamer in the tailstock. NO TAILSTOCK IS PERFECTLY ALIGNED WITH THE SPINDLE!!! while you can adjust a tailstock side to side, the vertical will always be off and changing as the bed and tailstock wears. Quality gunsmiths of yesteryear used a dead center in the tailstock and pushed the reamer like that, an early form of a "pusher" however the dead center kind of locks the reamer in the center hole on back of the reamer. It is important to note that they also were using a steady rest and the barrel somewhat floated, so the floater was on the barrel instead of the reamer. However if you chamber through the headstock like i do, using a spider on the outboard, you need to use a homeade "pusher" or a floating reamoer holder as this method the barrel is locked solid and will not float. I find my pusher quite good and have never cut an oversize chamber with it. Easy to make too.

leftiye
09-17-2013, 05:32 AM
How do you get "off center" of the bore if you indicate in the barrel? Unless of course you are using a steady rest, where you are reliant upon the OD. That will never make a good chamber. If you turn the OD concentric to the bore, then you'll be closer. But if for some reason you have a barrel where the bore is not close to the OD (which I have one right now, a Remington) the only way to set it up is using a set-true or 4jaw.

Floater or not, you can't ream a chamber if the bore is not indicated in.

"Floater or not, you can't ream a chamber if the bore is not indicated in." Horse feathers! You personally might not like the idea, but it's no where near impossible, and it's arguably not such a bad method.

You shouldn't be off center if you do it yourself, BUT. If you are rechambering a barrel someone else already buggered up and are using a steady rest things can be a little surprising. I guess you could indicate on the old chamber (and hope it is coaxial), and recut the OD of the barrel, but that's no guarantee either. I've seen at least one new Krieger barrel that was pre contoured that was neither straight nor co axial in/out, and many many Remington and other production barrels. In rechambering you're better off following the old chamber, I guess you could put a pin gauge in the bore, center and single point the sides of the chamber to true it up. Still no guarantee of coaxiality.

In all of this you may have noticed that I never said this was better than cutting a chamber in a bore (not rechambering) that had been zeroed. Using floating reamer holders was standard practice back when I started, and it isn't usually anything resembling a disaster. The reamer will follow the bore if you let it. trying to stop the reamer from following the bore (chucking it in the tailstock), that can be a disaster. As for first principles, that is one place where rigidity is counter productive.

B R Shooter
09-17-2013, 06:45 AM
HORSE FEATHERS! Give me a break, who in their right mind would ever chamber a barrel if it isn't indicated in? PLEASE! And you can't align a tail stock? HORSE FEATHERS!

To each his own.

So you have a reamer that hopefully has removable pilots, there is clearance between the bushing and the reamer. You have clearance between the bushing and the lands. You have a reamer held in a holder that will move around. And you expect that reamer to follow that hole?

Or, you have a barrel in a steady, there is clearance between the fingers and the barrel OD, hoping the OD is close to concentric to the bore. Then add the above, and you expect a good chamber?

Barrel through the headstock, held rigid both ends. Barrel bore indicated both ends. some chamber first, some chamber last. Either way, drill the rough chamber undersized to within about .050 of the shoulder. Reach into this drilled hole with a .0001 or .0005 indicator to where the chamber throat will be. here is the critical place, where the bullet starts. Indicate the barrel in using the grooves as what you're reading, and adjust it as close to dead nuts as you can get it. Use a boring bar, and now bore this drilled hole to within .010 of the shoulder diameter. Now you have a barrel perfectly aligned at the throat, the chamber body bored perfectly concentric to this throat. The reamer will glide right through, very little wear on the reamer, and the last .050 will be a breeze. The chamber will be perfect, it will be concentric and very minimal run out. This is how you do a first class, match grade quality chamber.

I wouldn't waste my time with all this on trying to resurrect a junkyard barrel.

leftiye
09-17-2013, 07:39 AM
So what is it that's indicated in when using a steady rest? The OUTSIDE OF THE BARREL! The bore is wherever it is. Not indicated in (zeroed). That's how it is when the chamber is cut. Who said anything about hopefully having a bushed pilot on the reamer? A plain pilot reamer will follow a bore. Who said anything about utmost perfect chamber? It's not the best , I said so in my first post here.

I was making the case that sometimes you need a floating reamer holder. And it's not the worst either, most of them done with a steady, and a floating reamer holder shoot fine. Maybe not .009" groups, but not everybody shoots benchrest. None of the production barrels in Remingtons and etc. have match chambers, nor are they cut as you describe. Many of them will shoot .250 groups, many more 1/2 MOA. Oh, and let's not forget that that isn't about just the chamber.

Many times a person has a gun that they want made 7mm 308 for instance from 7mm Mauser for instance. Rechambering is done a lot. Not everyone can afford any of the $350 and up barrel blanks, nor do they have a ghost of any need for them. Not often are they disappointed either.

B R Shooter
09-17-2013, 02:34 PM
'Nough said......

W.R.Buchanan
09-17-2013, 04:03 PM
Floating Reamer Holders are common tools used on Screw machines. I have one that I use frequently on my manual turret lathes.

They float "Axially," meaning the centerline of the reamer is parallel to the centerline of the work. This prevents them from "boring the hole, " which would happen if they are held off center by some gross misalignment.

It is totally possible to align anything with anything else. All you have to be able to do is indicate it some how. IN the case of a tailstock you hold the indicator in the headstock and spin it around the tailstock center. This will tell you exactly how far off the relationship is.

If you are driving a Chambering Reamer by using a center in the rear then the amount of misalignment is the only factor that will cause problems. Perfect alignment is not completely necessary and a couple of thou out of alignment is not going to change anything in the barrel since the reamer is essentially floating, flexing, and self centering anyway. IE: it is following the hole just like a larger drill follows a pilot hole. It will only "Bore" the hole if it is forcefully held out of natural alignment.

If your tailstock is more than a couple of thousandths out of alignment in either the X axis (side to side) or Y axis, (up and down) or both, then you have other problems that need to be dealt with.

An Engine lathe must be set up correctly to begin with. That means first leveling it with a precision level that reads in increments of thousandths of an inch, ( a carpenters level is perfectly useless here, ) This is done lengthwise on the bed, and then crossways under the spindle, and again under the tailstock. When all three readings agree, you are then very close.

Then,,, you must verify that the machine is not turning a taper by turning two diameters on a rod that is as long as can be held between centers on the machine, and looking for the same diameter generated at each end with the same "X" axis offset.

This will insure that the bed of the machine's bed is not twisted, which would be the primary cause of misalignment of the centers in the first place. The lighter the machine is, the more likely this condition is to exist.

Typically larger lathes have four adjustment feet supporting the headstock and two more under the tailstock. Once you get the machine perfectly level then removing the twist is usually accomplished by adjusting the tailstock feet one way or the other.

If you can insure that you have acceptable alignment then a Floating Reamer holder is not required. However if any misalignment is present then that tool would certainly simplify the operation. Even so Floating Reamer Holders have a basic adjustment where by you align the tool with the spindle. They are not meant to correct gross errors in misalignment. The tool in the picture has about .010-.015 total movement. It must be aligned with the spindle during setup.

I hope this sheds some light on this operation.

The other pics are of a Starrett Precision Level used in setting up machines. It reads in increments of .005 per foot. I also have one that reads .0005 per foot, however it is kind of a PITA to use as the slightest whisp of wind or change in the temperature sends it off scale.

I was a Millwright for many years and set up literally hundreds of machine tools.

Randy

rbertalotto
09-17-2013, 06:59 PM
It always makes me wonder why people are so quick to go against the first principal in turning metal

Because the bore is NEVER straight. It is impossible to center a bore throughout the length of the chamber.

If the reamer is held rigid, the chamber will always be oversized, egg shaped or banana shaped.

drhall762
09-17-2013, 07:35 PM
In production barrels we always used a floating reamer holder. Purchased the ones I like best from MSC. If you start with an independent 4 jaw chuck and about a 4" dowel pin, you can indicate in petty close, say +/-.0005. The pilot on the reamer is going to follow the bore. You can't stop that. What you can do with a floating reamer holder is take most all the lateral pressure that might be exerted on the reamer away. Reamers lasts longer that way regardless of what anyone else says. Now understand, I have only chambered about 10,000 barrels in production on a CNC machine and probably 50 to 60 by hand. I use a floating reamer holder no matter how well I have aligned the tail stock and indicated in the bore.

B R Shooter
09-18-2013, 06:42 AM
Because the bore is NEVER straight. It is impossible to center a bore throughout the length of the chamber.

If the reamer is held rigid, the chamber will always be oversized, egg shaped or banana shaped.


Wrong!

drhall762
09-18-2013, 08:01 AM
The other answer is to use a pull through reamer. All the pressure is front loaded, no pushing.

B R Shooter
09-18-2013, 08:22 AM
OK, we need to take a step back here. We all need to realize there are more ways to skin this thing than what is being talked about.

First, I look at this in purely an accuracy stand point. I shoot bench rest and have done all my own barrels for 18 years. It is not a production effort, just the most accurate chamber I can make, on the most top grade barrels that can be had.

I realize most do not look at chambering in the same way. there have been thousands of chambers cut using a steady. And using a floater. And using both solid pilot and bushing reamers. So there are many variables.

Mr. Buchanan made some very good points, very logical and straight forward. Eck0313 has observed what many never have, there are variables on the inside even the most top grade barrels. Akajun stated that you can't align a tail stock. Rbertaloto said barrels aren't straight and it is impossible to ream a true chamber unless you use a floater. Drhall with the impressive number of barrels he has chambered uses a floater no matter what, and speaks of the lateral pressure on a reamer. A very good point to make, but often over looked by many. So many people use something like an open end wrench, or a handle with only one leg to hold the reamer. Talk about lateral pressure.

So again, please, my apologies if I have ruffled feathers, and let's all accept there are many ways to do this. we all have opinions.

MBTcustom
09-18-2013, 08:26 AM
Because the bore is NEVER straight. It is impossible to center a bore throughout the length of the chamber.

If the reamer is held rigid, the chamber will always be oversized, egg shaped or banana shaped.

Not so much. It's very common for me to see factory barrels that are drilled in an arc, but I have never seen an aftermarket barrels blank that was drilled in an arch. I can look down a barrel and tell you if there is a warp in the bore. I am getting better all the time, but right now, I am able to detect .005 warp in a 35 caliber barrel, and tell you where on the barrel the approximate crest of the arch is, just by looking through it and see the light reflections.

I started chambering barrels the way everybody recommends, and I didn't like the fact that when I looked down the barrel after it was mounted in the lathe, it was no longer straight. It was straight as it arrived and set on the bench, but when I decided to put it in the lathe, it was warped! That is unacceptable. I designed a way to hold the barrel with zero stresses so that it was as straight in the lathe as it was in my hand, and all of a sudden, getting the chamber straight became a walk in the park! I mean it's dead nuts perfect 4" into the bore, and all I did was tram in both ends and not stress the barrel.

Now, I designed my own reamer holder too. I was unimpressed with the offerings that were available, so I designed my own. It takes just a few ounces of pressure on a sharp reamer to make it cut an oversize chamber, so I wanted something that would give me a true float in X and Y, Pitch and Yaw.
Next time you ream a chamber, when you are getting close to full depth, stop and clean your reamer and the chamber of chips and oil. Slip the reamer back into the chamber to full depth by hand. If it doesn't stick a little when you try to pull it out, then you were cutting the chamber oversize. All chamber reamers are tapered, and if they cut the right size, then they should stick like a taper does.
Once you have the reamer stuck in the chamber, I dare you to put an indicator on the shank and check runout as you turn the chuck. Most peoples reamers will wobble like a munken dronkey and his downtain mew.
However, if you set it up correctly, there will be less than .002 runout over the entire length of the barrel, and the reamer shank.

Here's my reamer holder. It seriously needs a little blue pill LOL!
82104

W.R.Buchanan
09-18-2013, 02:04 PM
Tim: does your holder have "Axial Float" in the knuckle? or is the knuckle just loose.

WE are splitting hairs here but if the reamer holder does allow axial float, then if the reamer is not aligned perfectly 0/0, it is going into the bore the hole at an angle. It has to.

The flex of the tool may allow it to come into alignment.

I like the pull thru method the best as there is no way it can do anything but drag the reamer thru in alignment with the bore.

Like the guy said there's a lot of ways to do this job, however there are good ways,,, and no so good ways.

Randy

MBTcustom
09-18-2013, 02:54 PM
Yes, it has X and Y, Pitch and Yaw, the rubber cuff is there to keep it from falling apart where I cut the double dovtail. I was concerned that it might not work as intended, but I have reamed quite a few chambers with it and find that it actually works amazingly well, and get's me that tight fit on the reamer I was talking about. Everything else gets me close, but not perfect.
Of course, I bore the hole pretty close to size before I start reaming.

B R Shooter
09-18-2013, 05:31 PM
I have to say here, .002" runout in a finished chamber is too much. There is something wrong in the set up, or the lathe. Sorry, but it is entirely possible to get less than .001" easily.

DCM
09-18-2013, 07:16 PM
Floating Reamer Holders are common tools used on Screw machines. I have one that I use frequently on my manual turret lathes.

They float "Axially," meaning the centerline of the reamer is parallel to the centerline of the work. This prevents them from "boring the hole, " which would happen if they are held off center by some gross misalignment.

It is totally possible to align anything with anything else. All you have to be able to do is indicate it some how. IN the case of a tailstock you hold the indicator in the headstock and spin it around the tailstock center. This will tell you exactly how far off the relationship is.

If you are driving a Chambering Reamer by using a center in the rear then the amount of misalignment is the only factor that will cause problems. Perfect alignment is not completely necessary and a couple of thou out of alignment is not going to change anything in the barrel since the reamer is essentially floating, flexing, and self centering anyway. IE: it is following the hole just like a larger drill follows a pilot hole. It will only "Bore" the hole if it is forcefully held out of natural alignment.

If your tailstock is more than a couple of thousandths out of alignment in either the X axis (side to side) or Y axis, (up and down) or both, then you have other problems that need to be dealt with.

An Engine lathe must be set up correctly to begin with. That means first leveling it with a precision level that reads in increments of thousandths of an inch, ( a carpenters level is perfectly useless here, ) This is done lengthwise on the bed, and then crossways under the spindle, and again under the tailstock. When all three readings agree, you are then very close.

Then,,, you must verify that the machine is not turning a taper by turning two diameters on a rod that is as long as can be held between centers on the machine, and looking for the same diameter generated at each end with the same "X" axis offset.

This will insure that the bed of the machine's bed is not twisted, which would be the primary cause of misalignment of the centers in the first place. The lighter the machine is, the more likely this condition is to exist.

Typically larger lathes have four adjustment feet supporting the headstock and two more under the tailstock. Once you get the machine perfectly level then removing the twist is usually accomplished by adjusting the tailstock feet one way or the other.

If you can insure that you have acceptable alignment then a Floating Reamer holder is not required. However if any misalignment is present then that tool would certainly simplify the operation. Even so Floating Reamer Holders have a basic adjustment where by you align the tool with the spindle. They are not meant to correct gross errors in misalignment. The tool in the picture has about .010-.015 total movement. It must be aligned with the spindle during setup.

I hope this sheds some light on this operation.

The other pics are of a Starrett Precision Level used in setting up machines. It reads in increments of .005 per foot. I also have one that reads .0005 per foot, however it is kind of a PITA to use as the slightest whisp of wind or change in the temperature sends it off scale.

I was a Millwright for many years and set up literally hundreds of machine tools.

Randy

Where is the like this post feature when you need it.
Hmmm experience,knowledge and common sense combined.

leftiye
09-19-2013, 05:01 AM
The other answer is to use a pull through reamer. All the pressure is front loaded, no pushing.

Yes, this accomplishes the same thing. Zero constraint (rigidity) on the rear of the reamer. Not many of these around though.

leftiye
09-19-2013, 05:20 AM
I have to say here, .002" runout in a finished chamber is too much. There is something wrong in the set up, or the lathe. Sorry, but it is entirely possible to get less than .001" easily.

I have to say here - you're worrying about something that doesn't matter. It is probly easy to demonstrate that the difference on paper between a "perfect chamber" and one within .002 isn't observable, especially depending on how it is out - how it varies from what is measurable perfection.

Differences - which are undetectable, between barrels make more difference. Small differences in bedding, receiver trueing, lug lapping can make more difference. Ammo which is out coaxially can have a lot more effect. To include differences you can't measure like differences between bullets. Forty years ago we knew about lug lapping and receiver truing, but virtually nobody was doing it. About that time the first perfect group was shot in a match. FWIW. They called it a .009" group. Individual bullet holes on the sighter were larger than the group. More than .002" larger.

MBTcustom
09-19-2013, 06:21 AM
I have to say here, .002" runout in a finished chamber is too much. There is something wrong in the set up, or the lathe. Sorry, but it is entirely possible to get less than .001" easily.

I said .002 over the entire length of the barrel. The reamer shank should be nearly unmeasurable.

B R Shooter
09-19-2013, 07:06 AM
I stand corrected, that is what you wrote.

W.R.Buchanan
09-20-2013, 09:22 PM
DCM: HA! fooled ya again!

Not really, thanks for the kind words.

I feel it is the responsibility of a craftsman to make sure everything he knows is passed on to the ones who follow.

Just look at the amount of knowledge this world has lost from those who have passed and not passed their knowledge down.

We should be way out in space by know, but instead we are trying to figure out how to defund Obamacare!

Randy

Willbird
09-25-2013, 12:32 PM
I have never used one, not even once.

When running a barrel on a steady I just turned the OD true to the ID, if you are dealing with the muzzle you can match the taper up close but a tad steeper so the turned part "fades out"...on the breech end you are turning the tenon true to the bore anyway before chasing a thread on it.

Many folks who have been in the trade a long time have developed methods to "push" a reamer without "steering" it.

One could also make or use an adjustible center for the tailstock that allows it to be dialed in.

Or actually quite simply just mount a boring bar in the lathe spindle and bore then ream a straight hole into an old morse taper drill shank (the shank is soft) for a light press fit of a straight shank center, mark which way goes "up".

On a steady I just adjust the steady so the barrel points right at the tailstock...on a 26" barrel you might be flexing it a few .001 to do that, if the tailstock is more than a few .001 high or low that should be fixed anyway :-).

I have a Grizzly lathe I use now, and indicating the tailstock center with an indicator clamped on the barrel is a good double check anyway, and it was within .001 TIR up and down, and the side to side you can adjust.

An older smith I know said there were two ways he knew to get into a "death chatter" with a reamer he BARELY got out of.

1. Use a floating holder
2. Step drill a chamber like some gunsmith texts say to do.

Bill