Grizzly Rod upgrade

My work on what you have humorously referred to as the "Gammuto Gazette" was a great learning experience. One thing that I learned is humility with respect for my writing...but we do the best that we can. In my defense, I will say that I probably did a lot of good for the self esteem of other writers, when they compared their work to mine.

As to my remarks about your remarks on "wrong" .....obviously, I skimmed a little too fast over that post. Gasp....choke...I goofed.

While we are here, would you please run through the effect, on sensitivity, of putting a very long probe, ( which would be needed to reach way down a barrel to do a direct measurement) on a lever style indicator. I got to thinking about a thread on the topic, and seem to remember that when you lengthen the probe, the value of the units on the dial changes. Do I remember correctly? I know that you have considerable experience in this area.
Boyd
 
Boyd Allen said:
My work on what you have humorously referred to as the "Gammuto Gazette" was a great learning experience. ... While we are here, would you please run through the effect, on sensitivity, of putting a very long probe, ( which would be needed to reach way down a barrel to do a direct measurement) on a lever style indicator. I got to thinking about a thread on the topic, and seem to remember that when you lengthen the probe, the value of the units on the dial changes. Do I remember correctly? I know that you have considerable experience in this area.

Boyd
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Boyd, actually I thought the Gammuto Gazette was a pretty good rag. It just came about as the WWW (World Wide Web) was coming in and with that unfortunately the printed page is on the way out unless someone reengineers the enterprise. And, yes, if the probe is extended on a given dial indicator the resolution decreases but some indicators, now, are geared for longer probes. It does take a high precision mechanism like an Interapid (model 312B-15 for example).



eddief said:
Man, I never knew three little 5/16ths ball bearings would cause this much static.............I think this cat has been skinned enough to call it dead.
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Eddie, I agree, but like I stated earlier the wiggler/ball/rodthingy is an ingenious idea. As to doing the trig, its an "ratio and proportion" problem. No trig functions needed.
 
I looked up the indicator that you mentioned. It took a little work to find that particular item. Evidently the dial is marked in half thousandths. (The best price that I could find was $240). In reviewing a clip from Gordy's video http://www.youtube.com/watch?v=aII2tbavKnM toward the end, where he was showing the result of his dialing in with the rod, it showed that he used an indicator graduated in tenths of thousandths, so if, as we agree, there is some loss of that resolution when it is used with the rod, relative to a direct measurement with a long probe indicator, he has some room before he gets down to half thousandths. Of course you are more familiar with this, but in looking around, it seems that the indicators that read to .0001 all have shorter probes, so it would seem that even though the 312B-15 is designed with a longer probe, the mechanism seems to have limits as to the available precision. In the real world, this may be an unimportant distinction, since one can easily interpolate useful values that are less than one graduation.

Added later: It would seem that whether one retrofits a .0001 resolution indicator with a longer probe, or buys one that came that way, the longer the probe, the less the resolution. Either way, the end result should be adequate to the task under discussion.
 
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JerrySharrett said:
No trig functions needed.
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True, but trig or as a ratio are both valid, both will give the same answer and either way is easy to calculate. As a ratio with a 12" rod reaching in 2" where the bushing has .0005" runout the indicator will see 16.66% less movement which is .000083" so the indicator will actually read .00042 runout. If we reach in the bore a bit deeper say 4" the indicator will see 33.33% less movement so with .0005" runout we then will see .00016" less movement so the indicator will actually read .00034" runout.

BTW I never intended to argue the validity of using a rod or not I was curious as to the actual loss of resolution. I posted the numbers so people could decide for themselves if the loss of resolution was acceptable to them.
 
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WSnyder said:
.....
BTW I never intended to argue .....
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Yhea, right. What about the "getting pissy" part or the "childish" part??? (your #35 I believe)

Actually I am sometimes both. It took me a lot of years, a lot of miles, and a few scars to get that way so don't disturb it!!!

And, thanks for the math.



To Boyd , on the Interapid indicator, it doesn't matter if it is graduated in 0.0005" or 0.0001", if it is a quality made indicator when it reads zero it is zero.

Nope, Interapids ain't cheap, but they are the best I've found, ever, or so far.
 
JerrySharrett said:
Ted you have apparently not done a lot of workpiece alignment in a lathe using a dial indicator if you can get a reading on it out to 9 decimal places (what it that? blue trillion, quad zillion???)
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hi all
jerry you can bash away at me as much as you like i have a thick hide and a low iq
but as stated if in the end result using both way's to set up a barrel if you both end up with the ind up the barrel and it is reading .00005
then there is no right or wrong .
you are just being pig headed about the thing.you say your way is best and f@#k the rest

regards tasy_ted
ps: and that's 1/2 of one 10 th of a thou or 50 mil of one 1nch:confused:
 
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tasy_ted said:
hi all
jerry you can bash away at me as much as you like i have a thick hide and a low iq

you are just being pig headed about the thing.you say your way is best and f@#k the rest

regards tasy_ted
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Ted, please point out where I wrote anything close to the "your way is the best and fucz the rest".

There are several ways that are used and have been used to chamber winning benchrest barrels but I know of none in the short-range benchrest environment that use a rod hanging way outside the bore to indicate on (exception is that many use a gage pin to dial in the muzzle bore while chambering).

Years ago, before many gunsmiths bought lathes that allowed through-the-headstock barrel fitting, they used a piloted centering tool and a steadyrest. This method worked in most cases if the barrel was reasonably straight in the chamber area. But when benchrest gunsmiths started using the through-the-headstock methods and indicating the bore on both ends the percentage of "good shooting" barrels went up quite a bit.

In the last 2 evenings I have gotten calls from older, experienced, benchrest gunsmiths. These guys have been gunsmithing their own, and sometimes for others, for a couple of decades. The most recent call I got was from a previous Super Shoot winner who does his own work. They all want to know what is this sticking a rod in a barrel and then indicating the outside all about? Thankfully I can go to youtube and link them to some videos. They haven't gotten back to me yet, I guess they are still laughing.

To me, the funniest one is http://www.youtube.com/watch?v=Ba3_3qseCB4&feature=related . The thread finish on this barrel is really going to be amazing with that much overhang. So much for workpiece rigidity.
 
LOL Jerry, don't you have to do some laundry to do or pack for the SS? Jeff said you were leaving on Wed. If you keep it up you're going to have to hire a body guard to follow you around at Kelbly's. Not sure I want to be to close to you there either, might be kinda like being the third guy lighting a smoke on the same match.:eek:

See you there
Dan
 
Dan H said:
LOL Jerry, don't you have to do some laundry to do or pack for the SS? Jeff said you were leaving on Wed. If you keep it up you're going to have to hire a body guard to follow you around at Kelbly's. Not sure I want to be to close to you there either, might be kinda like being the third guy lighting a smoke on the same match.:eek:

See you there
Dan
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Just trying to get along and keep some of these guys straight Danny. Besides I have you and Jeff to cover my back.
Hope to be there Thursday, you?
 
JerrySharrett said:
Just trying to get along and keep some of these guys straight Danny. Besides I have you and Jeff to cover my back.
Hope to be there Thursday, you?
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Was planning on being there on Sunday but my pickup just started blowing blue smoke, depends on the fix whether I make it at all now, will take it to the shop in the morning. If I get it back by Monday I'll drive up Tuesday if not oh well, story of my life sh-t happens.:mad:
 
Dan H said:
Was planning on being there on Sunday but my pickup just started blowing blue smoke, depends on the fix whether I make it at all now, will take it to the shop in the morning. If I get it back by Monday I'll drive up Tuesday if not oh well, story of my life sh-t happens.:mad:
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Its because of that old cheap fuel you are burning in it.
If you will go back to the more expensive stuff we were burning a couple of months ago the problem will go away.
 
JerrySharrett said:
Its because of that old cheap fuel you are burning in it.
If you will go back to the more expensive stuff we were burning a couple of months ago the problem will go away.
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Jerry, I always use the cheap fuel. I buy at Kroger when I can get $.40 or more off/gal.
 
JerrySharrett said:
Ted, please point out where I wrote anything close to the "your way is the best and fucz the rest".

There are several ways that are used and have been used to chamber winning benchrest barrels but I know of none in the short-range benchrest environment that use a rod hanging way outside the bore to indicate on (exception is that many use a gage pin to dial in the muzzle bore while chambering).

Years ago, before many gunsmiths bought lathes that allowed through-the-headstock barrel fitting, they used a piloted centering tool and a steadyrest. This method worked in most cases if the barrel was reasonably straight in the chamber area. But when benchrest gunsmiths started using the through-the-headstock methods and indicating the bore on both ends the percentage of "good shooting" barrels went up quite a bit.

In the last 2 evenings I have gotten calls from older, experienced, benchrest gunsmiths. These guys have been gunsmithing their own, and sometimes for others, for a couple of decades. The most recent call I got was from a previous Super Shoot winner who does his own work. They all want to know what is this sticking a rod in a barrel and then indicating the outside all about? Thankfully I can go to youtube and link them to some videos. They haven't gotten back to me yet, I guess they are still laughing.

To me, the funniest one is http://www.youtube.com/watch?v=Ba3_3qseCB4&feature=related . The thread finish on this barrel is really going to be amazing with that much overhang. So much for workpiece rigidity.
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hi all
jerry just go back and look at all the post,s about gordy,s rod,s and look at all you post,s with out trying it ( i assume ) you bag it and those that do use it.

( the only down side to this way of setting up is the rod to bushing slop but if as gordy does you then drill and ind at the throat then bore out) all is good

regards tasy_ted
ps: the youtube video is not showing how gordy set,s up.???:confused:
 
In the video, Gordy has his indicator set up to read horizontal motion. Some fellows are doing it a little differently. Thy hang a small weight on the rod, and measure vertical movement. I think this variation would take care of all of the clearance, both between bushing and barrel, and bushing and rod.
 
Boyd Allen said:
In the video, Gordy has his indicator set up to read horizontal motion. Some fellows are doing it a little differently. Thy hang a small weight on the rod, and measure vertical movement. I think this variation would take care of all of the clearance, both between bushing and barrel, and bushing and rod.
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hi all
boyd yes i also think that this step take,s care of the clearance problem .:D

regards tasy_ted
 
One thing to note about Gordy's method is that he is only using the Grizzly rod to get him pretty close. If he's reading .0001 on the rod 3" away from the bushing, it doesn't make a spit if it's actually .001", it's a reference measurement that he drills and rough bores the chamber to. He does this so he can get a short arm indicator up to the throat to give him a true measurement of the actual run out. His rough boring job will allow the body of the indicator to pass into the chamber area on most calibers so he can then dial in the bore dead true at the throat and then clean up his rough boring job. Then he runs the reamer in for finish chambering.

Did I tell you guys about the 30-06AI I rechambered into a 300WM? I dialed in the existing chamber performed by a well known gunsmith using an Interapid on the chamber body in 3 places. Got it dialed in pretty darn good (the chamber wasn't exactly round but three jaws measured .0001" or less). So now I'm ready to chase the exiating chamber as if it were a pre-bore scenario. Turn the lathe on and see the threads bouncing up and down. Customer was standing there and told me to run the reamer on in there and it would be an experimental bbl. Damn thing would touch bullets @ 100 yards with military sniper grade ammo!!! Blew my mind...
 
Superman,
Can you tell me advantage of doing it that way against indicating both ends, drilling, indicating the throat, boring, and reaming? Both will be indicated to the throat and also how much will the barrel bore move direction in the inch beyond the throat? Would you know or is it a guess?
 
Butch, I've dialed barrels in at the throat through the chamber area and seen the run out on the muzzle end. I have a process that works really well for me and I'm doing well with it. My customers are more than happy with the results.

I know this is heresy, but I'm starting to think that if 3 of the 4 components of a gun build are good, the rifle will shoot acceptable to most customer standards and in accordance with the industry standard 1/2MOA accuracy guarantee.

I've seen barrels that slugged sketchy shoot lights out. I've seen crappy chambering/threading jobs that shot lights out. I've seen rifles bedded in bondo shoot lights out. I've seen ammo shoot lights out that, well, you wouldn't expect (fireforming 6Dasher rounds with big bells on the neck). This .300WM project I recently worked on is adding to that theory.

I will continue to do the absolute best work I possibly can, but it helps me understand why so many different methods of "skinning the cat" seem to work for others.

Bobby Keigans
www.freedomgunworks.com
 
Bobby,
I think all of us that have been around the block can relate. I just can't see any advantage of one method over the other. You mentioned an out of round chamber. I've done a lot of playing around and haven't been able to make an out of round chamber. I can do all kinds of goofy things to the chamber, but can't prodce one that is out of round. Certainly not saying it can't be done, but how can you do it.
 
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