# I think I want a 6 jaw chuck?



## LVLAaron (Mar 1, 2022)

I'm looking at a 6 inch set-tru TMX 6 jaw for my 1440. 

I'm chambering barrels so the "set tru" part is great... and I'm also working on a dozen other little trinkets so something quick is also nice.. Am I missing anything? Are they easy to fine tune down to a single tenth like I can with a 4 jaw?


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## Beckerkumm (Mar 1, 2022)

Others here will have more experience but my set tru is repeatable within .0005 but I don't consider it to repeat to .0001.  If others disagree I will have to work on my technique.  Dave


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## Liljoebrshooter (Mar 1, 2022)

Using a chuck to just clamp onto a barrel makes difficult to indicate them without binding.  You mentioned in another thread about a grizzly rod.
The barrel needs to be able to pivot to set them up like that. 
Joe


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## LVLAaron (Mar 1, 2022)

When doing a barrel, I don't care about the repeatability of the chuck - I'd use the set-tru "function" and true it up. I'd still run the barrel in a copper ring and manipulate with the outboard spider just like with a 4 jaw. 


But I also want to be able to quickly toss some round stock in it and face it off without getting out an indicator etc etc... 

Best of both 3 and 4 jaw worlds?


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## Watchwatch (Mar 1, 2022)

I love mine. Rarely comes off the lathe. 


Sent from my iPhone using Tapatalk


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## LVLAaron (Mar 1, 2022)

Watchwatch said:


> I love mine. Rarely comes off the lathe.
> 
> 
> Sent from my iPhone using Tapatalk



Would you say it's more or less work to adjust than a 4 jaw?


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## Cadillac (Mar 1, 2022)

Less work you will only be adjusting a .001 or 2. You have the advantage of the scroll chuck with the 4jaw capability to dial it in.


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## LVLAaron (Mar 1, 2022)

Sounds good to me! Swapping chucks is not something I want to do very often!


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## Watchwatch (Mar 1, 2022)

LVLAaron said:


> Would you say it's more or less work to adjust than a 4 jaw?



Less work

I can get easily get .0005 TIR by varying pressure on the 3 scrolls and spinning the work. Takes a second. The 4 jaw only comes out for bigger work. 

12x36 lathe. 6in 6jaw, 8in 4jaw.


Sent from my iPhone using Tapatalk


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## LVLAaron (Mar 1, 2022)

5 tenths is a lot for a chamber - I'd have no problem dialing that down with the "set tru" part of the system?


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## benmychree (Mar 1, 2022)

I have never felt the need for a 6 jaw chuck, but do appreciate the Set Tru feature, have had one for many years, only thing I can think of is when chucking thin workpieces to avoid deformation.  Another thing, it is a PITA to turn around 3 two piece jaws, doubly that for six.


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## mikey (Mar 1, 2022)

6 jaws hold slippery stuff like plastics better than a 3 jaw. That and thin-walled tubing is where a 6 jaw is useful. It will not clamp down as well as a simple 3 jaw chuck will so unless you need to do a lot of tubing or plastic I think your money is better spent on things you need.


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## benmychree (Mar 1, 2022)

mikey said:


> 6 jaws hold slippery stuff like plastics better than a 3 jaw. That and thin-walled tubing is where a 6 jaw is useful. It will not clamp down as well as a simple 3 jaw chuck will so unless you need to do a lot of tubing or plastic I think your money is better spent on things you need.


Amen


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## mksj (Mar 1, 2022)

Technically a Set-Tru is more to center the jaws for repeat work as opposed to using it to center the work piece. Except for very small changes in TIR (under 0.001") you need to loosen the chuck mounting bolts and adjust the TIR, then tighten them and hope that the TIR stays true. I have a 3J scroll Set-Tru as well as a 5C Set-Tru and I do not readjust them for centering stock. Also as Mike indicated the holding ability is more limited on a 6J. If you are looking for a chuck with a wider adjustability on the fly as well as a scroll, then you might look into a combination 4J 8" chuck. The scroll repeats to around 0.001" and each jaw rides on a scroll plate that is the same as an independent chuck. The 4J will hold stock down to 0.2" and you can tweak each jaw pressure for great holding power. A number of forum members as well as myself have the Bison version, it is a great chuck, and very versatile. The other thing to think about is cleaning the swarf out of these chucks, it can be a real PITA the more jaws you have.




__





						Bison
					






					bison-america.com


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## xr650rRider (Mar 2, 2022)

What all the cool kids are using.  True bore alignment system.  But not sure any of the record setting gunsmiths are.


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## erikmannie (Mar 2, 2022)

I have a TMX Set-Tru 6J scroll chuck as well as a TMX 4J independent.

They are both easy to dial in. I can dial in my 4J to .0001”. I could only dial in my 6J to .0003”.

The 4J is easier to dial in because there are only 4 adjustment points (the jaws).

The 6J has 4 adjustment points (the fine adjustment bolts), *plus* the 3 hex sockets to tighten down the chuck after you zero it in.

I have 4 Polish chucks, & I really enjoy all of them.

My question is: if you own a Set-Tru 6J scroll chuck, would you ever need any type of 3J scroll chuck?


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## mikey (Mar 2, 2022)

A simple 3 jaw will handle the VAST majority of all first operations work. It grabs better, is balls on accurate for first op work and is simple to maintain. As noted, unless you do a lot of plastic or tubing work, a 6 jaw is nearly superfluous in my opinion. 

Much is made of set-tru chucks but unless you are doing production runs they are no more accurate than a simple 3 jaw for first op work.

I think too many hobby guys think 6 jaws are vital when they will sit on a shelf when used appropriately. Eye candy.


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## davidpbest (Mar 2, 2022)

This is the 4J Combination chuck Mark was referencing above.  It's a scroll chuck but each jaw is also independently adjustable.  PTS was having a sale on them a few years ago, and several users here loaded up on them.  It's also available for less in a "semi-steel" body (7-848-0800).









						Bison 8" 4 Jaw Combination Manual Chuck Plain Back 7-849-0800
					

Bison 8" 4 Jaw Combination Manual Chuck Plain Back 7-849-0800




					www.smalltools.com
				




I believe this would be the appropriate back plate for D1-4:









						Bison Set Tru D1-4 Adapter Plate 7-875-084 for 8" Chucks
					

Bison Set Tru D1-4 Adapter Plate 7-875-084 for 8" Chucks




					www.smalltools.com


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## benmychree (Mar 2, 2022)

I have been using a Buck 10" set tru chuck on my 19" Regal lathe for about 40 years now and have not found it necessary to completely tighten it onto it's backplate as was suggested in a post above; it can be tightened reasonably tight and still allow a wide range of adjustment without any problems with ridgidity or chatter, wobble or what have you. It works just fine.


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## rabler (Mar 2, 2022)

mikey said:


> A simple 3 jaw will handle the VAST majority of all first operations work. It grabs better, is balls on accurate for first op work and is simple to maintain. As noted, unless you do a lot of plastic or tubing work, a 6 jaw is nearly superfluous in my opinion.
> 
> Much is made of set-tru chucks but unless you are doing production runs they are no more accurate than a simple 3 jaw for first op work.
> 
> I think too many hobby guys think 6 jaws are vital when they will sit on a shelf when used appropriately. Eye candy.


I tend to agree with this.  I have a couple 6 jaw set tru from an auction and they aren't the end-all chuck you might think.  I take it as a challenge to sit down and think through what I'm turning and what things need to be concentric, then make sure those all get turned as much as possible in one setup on the three-jaw.  Even if your three jaw is .010" off center, if you start with raw stock and turn features, those features will be concentric to within the spindle runout if they are done in the same setup without re-chucking things.  You can't do better than that with a different chuck.

For rechucking, 4-jaw vs set-tru makes little different.  Best use for the 6-jaw is when I've turned softer plastics to get good grip without deforming it.  

From a flexibiliity standpoint, I would tend toward having a 6-jaw in the smaller end of the chuck size range, say a 6" (from the perspective of my 14.5" swing lathe), and larger for the 3 jaw, then 4 jaw.


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## LVLAaron (Mar 2, 2022)

I needed a proper mill vice as well, so placed an order at Ajax Tools last night for the chuck and vice - will be here tomorrow. Dang they work fast!


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## ddickey (Mar 2, 2022)

I've got a three jaw scroll/independent and it's fabulous but I only paid $80 for it.  I don't really care for the  length of the chuck though but if the job calls for turning a piece for a second op it can easily be dialed back within a few tenths.


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## Beckerkumm (Mar 2, 2022)

I have an old Union combination chuck.  they were very high quality.  Steel with a high rpm limit.  Dave


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## Earl (Mar 3, 2022)

Here is a picture of my 6 jaw set tru Buck 6 inch chuck.   I do most all of my chambering with it.   I got it new and immediately had the jaws EDM'd off very close to the chuck face.  I use the ring at the bottom of the picture as a pivot point for the barrel.  I like to have the minimum sticking out of the chuck when I machine the chamber end of the barrel.   I tried one of the tru-bore devices that a buddy of mine had sitting in a cabinet. It does work but it is a pain to adjust for minimum (attempting to get to zero) runout.   After cutting 2 chambers with it I realized why it was sitting in a cabinet.  I also have one of Bob Pastor's sleeves (sold by Grizzly) for chambering barrels that are too short for my headstock and for doing bolt work.   It is also a pain to adjust because the adjustment points are only about 5 inches apart.   I took a d1-5 chuck adapter and made it into a spider.  I now use that to chamber short barrels.  I picked up about 3  inches from the 6 jaw.  Since the adjustments are at the ends of the barrel, it is much easier to indicate for minimum runout.

That cutter in the chuck (indicated for minimum runout) is for making boat tail bullet punches.  You put the blank in a holder in the tailstock, put a tight fitting sleeve over the cutter and the blank and use the tailstock handwheel to cut the boat tail punch to proper depth.


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## Liljoebrshooter (Mar 4, 2022)

Hey Earl,  what material are you using to make punches?  I have tried a couple and have had problems with the ends not breaking. 

Joe


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## LVLAaron (Mar 4, 2022)

Earl said:


> Here is a picture of my 6 jaw set tru Buck 6 inch chuck.   I do most all of my chambering with it.   I got it new and immediately had the jaws EDM'd off very close to the chuck face.  I use the ring at the bottom of the picture as a pivot point for the barrel.  I like to have the minimum sticking out of the chuck when I machine the chamber end of the barrel.   I tried one of the tru-bore devices that a buddy of mine had sitting in a cabinet. It does work but it is a pain to adjust for minimum (attempting to get to zero) runout.   After cutting 2 chambers with it I realized why it was sitting in a cabinet.  I also have one of Bob Pastor's sleeves (sold by Grizzly) for chambering barrels that are too short for my headstock and for doing bolt work.   It is also a pain to adjust because the adjustment points are only about 5 inches apart.   I took a d1-5 chuck adapter and made it into a spider.  I now use that to chamber short barrels.  I picked up about 3  inches from the 6 jaw.  Since the adjustments are at the ends of the barrel, it is much easier to indicate for minimum runout.
> 
> That cutter in the chuck (indicated for minimum runout) is for making boat tail bullet punches.  You put the blank in a holder in the tailstock, put a tight fitting sleeve over the cutter and the blank and use the tailstock handwheel to cut the boat tail punch to proper depth.



That's a nice setup. I've got a d1-5 backplate I'm going to do the same thing with. Do you make your own bullets?


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## Jason812 (Mar 4, 2022)

xr650rRider said:


> What all the cool kids are using.  True bore alignment system.  But not sure any of the record setting gunsmiths are.


Whole lot more expensive than a set of home made spiders too.


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## LVLAaron (Mar 4, 2022)

True Bore Alignment System is a really interesting kit. The people that have them aren't using them on 1440's. Gordy has one in his shop, doesn't really use it. Gavintube (ultimate reloader) has one, but got a bigger lathe to use it. He talks about it a little bit in his new lathe video


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## Earl (Mar 4, 2022)

Liljoebrshooter said:


> Hey Earl,  what material are you using to make punches?  I have tried a couple and have had problems with the ends not breaking.
> 
> Joe


I just re-cut old punches.  When I mess them up, I usually only get the top 10 to 15 thou of the punch.   I have 2 cutters.  One is for a .070 boat tail and the other is for a .090 boat tail.   My dies make .070 boat tail bullets.  My setup consists of the cutter in my set tru chuck, a hardened sleeve that is a close fit to the cutter, and an er25 collet chuck with an MT3 shank for the tail stock.   The cutter and sleeve is from Biker Engineering in Southern California.  Setup is critical.  I dial in the cutter until I cant see the needle move on the best test .00005 indicator.   That sometimes takes a while.  Next I mount the punch in the er25 collet, and put the collet into the tailstock.   Next is the fun part.  I slip the sleeve over the cutter, bring the tailstock up close to the cutter and try to slide the sleeve over both the cutter and the punch.   It almost never goes on the first try.  I have to play with rotating the punch in the collet to get the tolerances to add up in my favor.   Once I get the sleeve to slide over the punch and the cutter,  I know that they are aligned.   At that point, it is a guessing game as to how deep I go with the cutter.   Even though it is a carbide cutter,  I go really slow.  20 rpm or so.   I just touch the punch and stop, move the tailstock back and measure.  Rinse and repeat until I get the depth I want.
When I think I am finished, I take the punch out, put it in some precision v blocks and measure the runout on the inside of the top of the punch.  If it runout is a tenth or less.  I make bullets.  If it is more than that, I start over.   I absolutely hate making bullets.  The only reason that I do it is because it is one more thing that I have control over.  

Pinehardt sells punches that have a crown in their base.  I creates a dimple in the bottom of the bullet.  Looks cute but I dont know what difference in bullet performance it will make.  I will find out next week at the Cactus match .   Lester gave me one of his punches  (our dies are almost identical) and I made 750 bullets with the dimple in the bottom.


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## Earl (Mar 4, 2022)

LVLAaron said:


> True Bore Alignment System is a really interesting kit. The people that have them aren't using them on 1440's. Gordy has one in his shop, doesn't really use it. Gavintube (ultimate reloader) has one, but got a bigger lathe to use it. He talks about it a little bit in his new lathe video


With all due respect to Ulimate Reloader,  I have not seen any of his stuff in competition.  I have not seen him in any competition.  Talking about accuracy is one thing but it doesn;t mean a thing unless can display it in competition where there is a time limit and a judge to do the target measurement.


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## Liljoebrshooter (Mar 4, 2022)

Never thought about putting the cutter in the left hand and holding the punch stationary. 
I will have to do some thinking about a new setup. 
No comments about the other punches.   Momma always said "if you don't have anything good to say , keep your mouth shut "
Thanks for the information Earl.   If you see Chuck tell him I said hello. 
Joe Hynes


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## Earl (Mar 4, 2022)

Liljoebrshooter said:


> Never thought about putting the cutter in the left hand and holding the punch stationary.
> I will have to do some thinking about a new setup.
> No comments about the other punches.   Momma always said "if you don't have anything good to say , keep your mouth shut "
> Thanks for the information Earl.   If you see Chuck tell him I said hello.
> Joe Hynes


Chuck is having some medical issues but he is in good spirits and is still one hell of a competitor.  Back in December, he fell at the range loading up his golf cart.  He was in bad shape for a while.   At the February match, everyone kept coming up to him asking about his health.   I finally told him that "They dont care about your health, they care about the bullets that they ordered from you."   He got a serious look on his face and finally said "I guess you are right."   He is a really good guy.  Him and Bob Brackney love to compete against each other.  I have seen electric signs at the range during a match that said "BEAT MILLER"  There were hats made a while back that said "BEAT BRACKNEY."


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## LVLAaron (Mar 4, 2022)

Earl said:


> With all due respect to Ulimate Reloader,  I have not seen any of his stuff in competition.  I have not seen him in any competition.  Talking about accuracy is one thing but it doesn;t mean a thing unless can display it in competition where there is a time limit and a judge to do the target measurement.



I wasn't saying he's a good or bad rifle builder. He does seem to know how to operate a machine though. I'm just saying that there are people with 1440 sized lathes that don't use them. Not sure if it's too much weight hanging off the spindle or what, but I'd like to know if there's any merit to it.


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## xr650rRider (Mar 5, 2022)

Gavin was saying it caused a lot of imbalance in his 1440, so he could justify a new 1660.  I couldn't see anything that introduces that much out of balance being any better in a bigger machine.  Closer to the spindle seems better.  The bigger machines, that device other than chambering between centers, might be your only option.  If you can dial-in to <.0002" directly on lands with inboard and outboard spiders or a 4 jaw, how can such a device be any better?


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## LVLAaron (Mar 5, 2022)

Better is a matter of preference. I like the idea for chambering say a 20 inch AR barrel. But then again something else like a truing  jig would suffice I believe.


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## xr650rRider (Mar 5, 2022)

With an inboard spider close to the spindle, I can do 19" on a PM-1340GT.  With a 4 jaw or 6 jaw, you'd give up 2-3" at least.   If I have a muzzle thread, I made some bars that I can screw on and extend the barrel length 12".  I've got bars that are threaded with most action threads that I can extend short barrels with as well.


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## LVLAaron (Mar 5, 2022)

I had thought about adding a tube to extend the barrel to the outboard spider. I guess there’s no reason it won’t work as long as the fit up is adequate


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## xr650rRider (Mar 5, 2022)

There is always another way to skin a cat.  The cat doesn't like any of them.


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## Liljoebrshooter (Mar 5, 2022)

That fixture looks like it would remove money from your wallet really good.
I see no reason to spend that much money for it.  But if you got it good for you. 
I have done a couple barrels now and done ok with them. 
Joe


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## Firebrick43 (Mar 5, 2022)

Earl said:


> With all due respect to Ulimate Reloader,  I have not seen any of his stuff in competition.  I have not seen him in any competition.  Talking about accuracy is one thing but it doesn;t mean a thing unless can display it in competition where there is a time limit and a judge to do the target measurement.


With all due respect, he didn't say in could be more accurate overall.  He stated that it was a system that could have a much faster set up than his current system of aluminum pads under chuck jaws and a homemade outboard spider.


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## LVLAaron (Mar 11, 2022)

Got a Buck B8066 today. I originally ordered a TMX 6-jaw buck everything TMX is on a boat or back-ordered at the moment. (And not a lot of faith for things coming out of Poland right now with the war in the their back yard) 

Looks to be VERY nice. I don't have it on the machine yet but I'm looking forward to it.


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