? chucking up a barrel ?

As to a thread gage why not just use 3 1/32" drill bits like they recommend on the Panda drawings?

I lucked into a DoAll 1-1/16-18 inspection gage a few years ago. I saw another one in eBay while back for $150!!

This does not solve the timing problem though.

Kelblys use one of their threaded inserts with degrees engraved on the outside for timing where the printing comes out.
 
JerrySharrett said:
As to a thread gage why not just use 3 1/32" drill bits like they recommend on the Panda drawings?

I lucked into a DoAll 1-1/16-18 inspection gage a few years ago. I saw another one in eBay while back for $150!!

This does not solve the timing problem though.

Kelblys use one of their threaded inserts with degrees engraved on the outside for timing where the printing comes out.
Click to expand...

Jerry,
I already have the insert. Thanks for the tip about engraving degree marks for the timing of the printing.

Best,
Dan Batko

"Where are we going and why am I in this basket?"
 
jackie schmidt said:
Fitch, as with all things in Machine Shop Work, the real truth is in the final inspection. Either it is correct, or it isn't.
Click to expand...

Gotta love the "no-spin" nature of working with hardware. It was pretty much the same in my previous life in Aerospace. We designed, did development, built prototypes, did qualification, built and tested the flight units and then launched them. "Them" were shuttle launched electronic boxes most of which did things that hadn't been done before on orbit, or sometimes ever. We used to say, "We have until it ships to get it right, mother nature and the customer have forever to see if we did."

Fitch
 
One other way to look at it, is to ponder how you would connect a chamber to a barrel, if they were separate items.
Say the chamber was part of the action and the barrel screwed onto the action and chamber.......How would you want that transition to be?

1. Perfectly aligned to the entrance of the barrel or

2. aligned to an imaginary axis that is 20-30" long, that everyone agrees is not straight.

Its no different than a river flowing or an intake manifold.....You have to shoot whatever, perfectly true into the axis of the entrance

Indicating the throat and the muzzle and calling that straight is impossible.

The bore of a barrel is, lets say....in a 3 dimensional reality, and letting the reamer float lets you get away with it. That's why the chamber is not really perfect with the tenon.

I guess what really matters is how accurate does it have to be, and that sounds like sub <.1 minute of angle .......that's a really small frog hair.

The bullet has to follow the longest path of the bore, anything less is cutting corners and I think we would all agree that ain't right.









'
 
TRA, that brings us to another item, how straight, or crooked, does a barrel's ID have to be so that it affects the agging capability.

The best barrel I own at the moment is the 30 caliber 1-18 on my HV. That barrels ID is so staright that when I chuck it up and gaze through the barrel as it is spinning, I can't see, (well hardly), any runnout.

The worst shooting ones sem to be the ones that have one of those "kinks" up up near the chamber.

I have heard shooters say that it makes no difference how crooked the ID of a barrel,. I don't buy that for one moment..

To give you an idea how bad some can be, I have taken barrels that, when placed between centers, showed no runnout on the OD. I would then have to take about 4 inches off the chamber end to make weight, and suddenly the thing runs out .009 .010 on the OD as compared to the ID. That means in just a 4 inch length, the Gun Drill took a turn. Then you look up in there and see a spot that for all appearances, might be running the opposite way. That cannot be a good thing........jackie
 
TRA,
You have trouble with reading comprehension. Nowhere does it say I indicate both pins and chamber. That is where I start my setup. Read it again. Now you guys that use the whippy indicating rod tell me how it can find 4" or so of straight barrel.
Butch
 
Butch Lambert said:
TRA,
Now you guys that use the whippy indicating rod tell me how it can find 4" or so of straight barrel.
Click to expand...

FWIW: The way I use my Grizzly rod, I indicate with it near the end of the breech, and then in about where the copper wire is located in the chuck jaws which is usually about 1-1/2 inches in the bore, then an inch to an inch and a half beyond that (which ever is just beyond where the throat will be). The end of the rod is in the tail stock chuck, the other end is in the bore.

I adjust the barrel so the point at the wire in the chuck jaws and the one 1" to 1-1/2" deeper are centered. If, when those two are centered and the one near the breech is also centered, I figure the section is both aligned with the lathe spindle and straight. If I can only get two points to indicate, I figure it is curved so I use a point at the throat and one an inch or so beyond. The way I'm using it, it doesn't matter if the rod isn't absolutely rigid, if it indicates centered at three points with out disturbing the barrel, the bore segment is straight and aligned with the lathe spindle.

The Grizzly rod is 12" long. When it's in the bore 3" the indicator is really about 3-1/2" from the bushing end so the 0.0001" indications on the DTI are really 0.00014". In practical terms, if I can get the three points centered +/- 1 division, I think it's pretty good - the reamer with a tight pilot will follow the bore and the chamber is both tight and aligned with the bore.

Based on what we've discussed here, if I can only get two of the three centered, I'll go for centering the one at the wire in the chuck jaws and the one 1" or 1-1/2" deeper in the bore. Then I'll drill, bore, and finish with the reamer. In theory that will give me a chamber that is aligned with the bore just beyond the throat and eliminate the oversize that would occurr from following the curve.

Fitch
 
Last edited by a moderator:
Fitch am I reading this right. You are concerned with the throat and an inch or so in front of that? Now tell me how much smaller your bushing needs to be to slide into the bore. Now while you are at it, how much clearance are there between the bushing and your whippy rod?
I put the throat area on the pivot point of my spider on the so called chuck side. Why not get a direct reading with the proper DTI at that point rather than a rod that has a bushing that is probably .0002 smaller than the bore and a bushing that has at least .0002 clearance on your rod to enable it to float and turn? Call Dave Kiff and check those dimensions.
Butch
 
Butch Lambert said:
Fitch am I reading this right. You are concerned with the throat and an inch or so in front of that? Now tell me how much smaller your bushing needs to be to slide into the bore. Now while you are at it, how much clearance are there between the bushing and your whippy rod?
I put the throat area on the pivot point of my spider on the so called chuck side. Why not get a direct reading with the proper DTI at that point rather than a rod that has a bushing that is probably .0002 smaller than the bore and a bushing that has at least .0002 clearance on your rod to enable it to float and turn? Call Dave Kiff and check those dimensions.
Butch
Click to expand...

Yes, that's exactly where I'm concerned about centering. I do it all the time. It works just fine.

The bushing slides into the bore, the rod and DTI apply a slight side pressure to it so I can literally see it roll over the ribs on the DTI needle, I don't worry about having a close tolerance fit - I routinely use the standard bushing that comes on the reamer.

This works because I'm looking to get something centered, not measured. The markings on the DTI are more representative of it's sensitivity than accuracy. I'm trying for a null, which requires repeatability, which is much different than trying to measure the distance between two points which requires accuracy. The ratio of the difference between the distance into the bore and the length of the rod divided by the length of the rod times the markings on the DTI determine it's relative sensitivity. Probing with the bushing 4" into the bore, with the DTI a half inch outside the bore, the 0.0001" DTI marking represents 0.00016" of bushing movement. At 6" the 0.0001" marking would represent 0.0002". If I wanted to measure farther into the bore, like for a .338 Lapua, I might like a longer grizzly rod.

If anyone can even measure an inch and a half beyone the throat (that would be 4.0" up into the bore for the .30-06 I just chambered) with a long probe DTI before the start of chambering (the only time the measurement is worth anything) repeatability is going to be laughable at best.

The bushing on the rod transmitting motion to a 0.0001" DTI us a lot more repeatable than a shakey DTI with a 4.0" lever on it reaching into the bore. Gordy's method can't be correctly implemented with out using a rod and bushing as the remote sensing element - at least in a home shop (having worked with NASA for 3-1/2 decades I'm pretty sure they could come up with a way to do it but we couldn't afford it).

Finally, anybody who indicates a throat to 0.0001" and thinks it's still there when the reamer is working or a cutter is cuttin on the tenon is fooling themselves.

Fitch
 
Fitch,
Quite preaching and look up a Mitutoyo 513-504 DTI indicator. What length probe does it have? What forum is this? I thought it was BR.Com. I don't know of anybody shooting a 30-06 or 338 Lapua in our matches. Please read again and tell me where I indivate a pin before I chamber. Quite typing and read first. #1 AGAIN- I indicate a Deltronic pin. #2- I predrill#3- I stick my 513-504 mitutoyo DTI indicator body and probe in the drilled hole. #4-I indicate the throat #5- I taper bore with a short stiff carbide boring bar.
#6- I ream with a loose bushing. My Mitutoyo has a 1/2" probe and not a long shakey one. Again look up the specs on it. You could use one.
You may want to examine your chambering methods if you're wanting a good way.
One thing to keep in mind as Turk Takano has long said"There are no perfect chambers because there are no perfect barrels".
I believe your mind is closed and you have sipped the Kool Aid. I'm out of here.
Butch
 
Alla' youse guys that use those 12" long rods are indicating OUTSIDE the barrel. I don't give a damn what kind of pressure you are putting against the rod, the indicator probe tip is not touching the barrel bore, it is getting its reading OUTSITE the frikkin barrel~!!

I going with Butch~~~outta here!!!
 
alinwa said:
Please understand, Jerry and Butch, .....



al
Click to expand...

Don't mind me al, the way I test my work is in real competition, like the Super Shoot, the IBS Nationals, the NBRSA nationals, and a few little shoots like the Shamrock and a few other local 2-day events. Where you going to test your newly discovered methodology???
 
alinwa said:
Well, I believe Jackie will try it :)

And between Mike and Jackie they can lend some real "weight" to the argument....... so's you'se guys don't have to feel as if you're talking to children.

Please understand, Jerry and Butch, Fitch and I may be little and inexperienced (sorry Fitch, I'm making a point, ;) you may exclude yourself from my juvenile company, no ill will ) but believe it or not WE DO understand what you're saying! Whether you're outta' here or not you are being clearly understood.....

We just disagree :)

I'll even "agree to disagree" if that'll make you'se happier but don't go away mad.

I've been down this road quite a few times on this board on many subjects...... for some reason the subjects seek me out ....... and for some reason I'm ALWAYS in the minority. :) :)

Once I was even proven wrong (I think) by vibe on a muzzle brake issue..... or at least I haven't been able to prove HIM wrong..... but patience gener'ly prevails.

al
Click to expand...

Well said.

Like you, discussions like this seem to seek me out. They have all my life. Alas, I've been right most of the time. When I'm not and someone shows me that with facts, I'll agree with them immediately after I understand where I was wrong. I will do what's right when ever I can figure out what that is.

If one reviews my answers, they were objective, dispassionate, always based on facts that were related directly to the discussion at hand. No negative inuendo, no invocation of expertise not in evidence, just the application of physics related to the issue at hand. My goal in discussions is improved understanding so I am a huge fan of dialog as opposed to argument.

I use the .30-06 as an example of why the approach we use is better with a long cartridge. After Butch's reply, I went and looked and there have been a lot of long range BR matches won by .300 WinMAGs, 7mm magnums, and related long, and longer cartridges which are not all that different from the length of a .30-06 so it wasn't a bad example. .30-06 is still shot in some matches though not in short range BR. However that doesn't invalidate the point that the method that works best on long cartridges because it is theoretically correct is also best on shorter cartridges for the same reason. That said, for purposes of accurately punching paper (as opposed to dropping game animals) the BR and related "short" cartridges look really good at a thousand yards and for that purpose may be better than the more powerful ones.

I have great respect for Jerry, Butch, and the others on this forum. They've been there, done that, way more than I have. Jerry was a lot of help to me off line via e-mail when I did this last chambering project - a Sporterized '03 Springfield. He made several suggestions that were very helpfu. I've read and used information from Butch, Mike Bryant, and many others and it's helped me with my understanding. Even when I don't end up agreeing with them on a particular point, analyzing what was said has brought me improved understanding and the confidence to go forward. That was the case in this thread. But that doesn't mean I'm going to agree with them when the physics and other objective data says to "me" the point being made is not theoretically correct in the general case just because they are experts.

I drove some folks nuts in my earlier life because I didn't care who said something. If it was wrong, it was wrong. If it was right it was right. the statement had to stand on it's merits, not the reputation of who said it. (That's a Myers Briggs INTJ personality type FWIW.)

So, I am what I am. You are apprently wired much the same way I am. I can agree to disagree with Butch and Jerry on the subject of Gordy's method vs the muzzle breech method. I can do so with zero hard feelings and look forward to seeing more of their input and commentary because there is a good chance I'll learn something from it.

Fitch
 
frwillia said:
I drove some folks nuts in my earlier life because I didn't care who said something. If it was wrong, it was wrong. If it was right it was right. the statement had to stand on it's merits, not the reputation of who said it. (That's a Myers Briggs INTJ personality type FWIW.)


Fitch
Click to expand...

Fitch, I attended a Myers Briggs type indicator workshop/evaluation. I don't remember what mine was other than it had 4 alpha characters. It may have been EEEK !! It sure wasn't a Minnie Mouse reading!! (EEEK -Entro Extro Egod Kickimout??)
 
JerrySharrett said:
Fitch, I attended a Myers Briggs type indicator workshop/evaluation. I don't remember what mine was other than it had 4 alpha characters. It may have been EEEK !! It sure wasn't a Minnie Mouse reading!! (EEEK -Entro Extro Egod Kickimout??)
Click to expand...

Thanks!! I haven't had that good a laugh in weeks.

That was really good.

Fitch <still chuckling>
 
frwillia said:
Thanks!! I haven't had that good a laugh in weeks.

That was really good.

Fitch <still chuckling>
Click to expand...

Wonderful life wasn't it. About 1965 or so Kodak joined the Gimmick of The Month Club, and we did it all. The first one and probably the best was MBWA. Kind of like this divining rod thing that is the rage in chambering. MBWA, walk around it long enough and it will die on its own, which I hope the wiggledy-rod....NO... No, I hope everyone discovers this marvelous new technology and that everyone shoots wiggldy-rod barrels in 2011!!

The temp is now up to 24F and sunny. I'm gonn' go shoot.
 
To those confused and tired.

There are two basic methods.

1. Indicator method. Dial in the muzzle where it will be when done and where your reamer bushing will ride at the end of the chamber job using a test indicator only.
2. Rod method or Gordy Gritter's method. Dial in a few inches past the reamer bushing and at the chamber area using a rod with bushing that is being held by the tailstock chuck. The reading indicated is the difference between zero movement at the tailstock chuck end and the barrel, which has a bushing in between.

Indicator method The indicator reading will be very close to reality, meaning the reading is as pure as possible. Taper bore and chamber. The chamber, tenon, threads and bullet engagement area are true to each other. Perceived issue with this method is the area ahead of the indicated point being on an angle with the bullet. It is an authentic concern because we all agree there has to be some angle because the barrel is not straight. The degree of this angle depends on the quality of the barrel and how much we bend it by dialing in. This is the main negative issue with this method and the source of all concern according to rod users. The angle cannot be that bad with a decent barrel and lathe operator because this method has been proven for years and the groups on paper cannot be argued with.

Rod method If we use rods the angle mentioned above is almost eliminated. However, using a bushing lowers the quality of measurement because of play between the bushing and the barrel and the rod. Also, indicating at the middle of the bending rod lowers the resolution by half because of full movement at the barrel and zero at the tailstock chuck. I'm saying half, and I think we can all agree it is close to that but it would take varmit al to figure it out. The negative isue with this method is the loss if resolution when indicating and the source of all concern with indicator users.

Both methods cannot have induced deflection when chucking up the barrel.

The difference of opinion is whether or not the tiny angle due to the indicator method is better or worse than the loss of resolution when indicating using the rod method.

What I do.

On a quailty barrel I use the indicator method. Through the headstock I dial in both ends, reaching in to the throat area and to the final muzzle face area. I taper bore and cut the tennon almost to OD and stop the shoulder a little short. I recheck my throat indicator, last chance. I chamber deep, prep the breech face and cut the tennon OD and thread right up the the shoulder without a relief cut. I headspace by taking a skim off the shoudler.

On a bent barrel such as a factory rifle, I use the rods to dial in and the same proceedure after that. The reason I use rods is because of the angle after the throat. With the barrel bent badly I want at least some straight portion directly after the throat.
 
Questions from the inexperienced:
If one uses a 12" Grizzly rod, that is held at its end in a tail stock chuck, to indicate a spot that is 2" down the breech end of the bore, and the indicator is as close as it can be to the end of the barrel, and there is a small weight hanging from the rod to take the slack out of the assembly, would the actual amount of runout be approximately 10/12ths of what the indicator showed, and if the tip of the rod was advanced into the bore to a point that was 6" from the end, would it be 6/12ths? I realize that these ratios ignore the length of engagement in the tail stock chuck, and the distance from the end of the barrel to the closest position that the indicator tip can be positioned, but I am talking round numbers, to see if I have a grasp on the concept. Beyond this, if I have the ratios right, why would the information thus generated not be useful? Also, of a longer whisker is fitted to a test best type of indicator, does it not reduce the resolution in a similar way, unless it was originally manufactured and calibrated that way?
 
PEI Rob said:
To those confused and tired.

There are two basic methods.

1. Indicator method. Dial in the muzzle where it will be when done and where your reamer bushing will ride at the end of the chamber job using a test indicator only.
2. Rod method or Gordy Gritter's method. Dial in a few inches past the reamer bushing and at the chamber area using a rod with bushing that is being held by the tailstock chuck. The reading indicated is the difference between zero movement at the tailstock chuck end and the barrel, which has a bushing in between.

Indicator method The indicator reading will be very close to reality, meaning the reading is as pure as possible. Taper bore and chamber. The chamber, tenon, threads and bullet engagement area are true to each other. Perceived issue with this method is the area ahead of the indicated point being on an angle with the bullet. It is an authentic concern because we all agree there has to be some angle because the barrel is not straight. The degree of this angle depends on the quality of the barrel and how much we bend it by dialing in. This is the main negative issue with this method and the source of all concern according to rod users. The angle cannot be that bad with a decent barrel and lathe operator because this method has been proven for years and the groups on paper cannot be argued with.

Rod method If we use rods the angle mentioned above is almost eliminated. However, using a bushing lowers the quality of measurement because of play between the bushing and the barrel and the rod. Also, indicating at the middle of the bending rod lowers the resolution by half because of full movement at the barrel and zero at the tailstock chuck. I'm saying half, and I think we can all agree it is close to that but it would take varmit al to figure it out. The negative isue with this method is the loss if resolution when indicating and the source of all concern with indicator users.

Both methods cannot have induced deflection when chucking up the barrel.

The difference of opinion is whether or not the tiny angle due to the indicator method is better or worse than the loss of resolution when indicating using the rod method.

What I do.

On a quailty barrel I use the indicator method. Through the headstock I dial in both ends, reaching in to the throat area and to the final muzzle face area. I taper bore and cut the tennon almost to OD and stop the shoulder a little short. I recheck my throat indicator, last chance. I chamber deep, prep the breech face and cut the tennon OD and thread right up the the shoulder without a relief cut. I headspace by taking a skim off the shoudler.

On a bent barrel such as a factory rifle, I use the rods to dial in and the same proceedure after that. The reason I use rods is because of the angle after the throat. With the barrel bent badly I want at least some straight portion directly after the throat.
Click to expand...

You have summarized it nicely.

Fitch
 
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