K
kman
Guest
my buddys chamber seems to b out of round when u dial in the barrel using old chamber its showing out of round what causes this its about 1 and a half thousants out of round ,is this ok and how was this caused
JerrySharrett
Senile Member
Is it a factory or custom chambering? Is it 0.0015" TIR (total indicator reading)?
For a factory chamber, 0.0015" isn't bad. If it is a custom chambering, it should be some better, Could be caused by chambering in a steadyrest with the rest running on an out-of-round surface or it could have been finished the last few thousands turning the reamer by hand.
As to a chamber being 0.0015" out of round, it does not cause a dangerous situation.
Steelhead1
G Vanlier
Chamber Concentricity
Jerry,
I have an additional question kinda in the same area. When I bought my lathe the gentleman gave me deltronic pins, and I have seen discussions on this site about range rods made by Dave Kiff. The question is does the range rod method for centering the bore have any advantages or dis advantages over the deltronic pins? Which method do you utilize or prefer?
Jerry,
I have an additional question kinda in the same area. When I bought my lathe the gentleman gave me deltronic pins, and I have seen discussions on this site about range rods made by Dave Kiff. The question is does the range rod method for centering the bore have any advantages or dis advantages over the deltronic pins? Which method do you utilize or prefer?
JerrySharrett
Senile Member
Neither!!! When you indicate on either rod type, you are indicating on the extension of the curve OUTSIDE the barrel. Those and similar rods are fine to rough the barrel in but the final alignment should be done in the barrel.
In the chamber end the alignment should be at the point where the bullet exits the case neck and enters the barrel bore.
In the muzzle, it is important to indicate the grooves at the bore exit.
Steelhead1
G Vanlier
Thank you for the information Jerry.
Jerry,
How does a range rod indicate "outside the barrel?"
In my opinion the range rod acts just like a long indicator except much more versatile, longer, and appropriately applied MORE accurate for centering the are around the throat.
deltronic pins, I agree..... the only use for them is measuring holes.
al
JerrySharrett
Senile Member
Al, if you want to use a range rod, by all means use it. Keep in mind though that the tolerance stackup will take away much of what the indicator shows.
For example, the average home gunsmith only has bushings in 0.0002" increments. Then the fit of the bushing on the range rod can be up to 0.0004" (0.0002 for the bushing ID and 0.0002" for the range rod OD). Then there is a required clearance for the pilot bushing to fit in the barrel bore (about another 0.0002" or so).
Then look at where the dial indicator is taking its reading, about 1"-3" away from where the bushing is actually running. What photos I've seen of these rods in use, the indicator, in many instances, is a 0.001" type or in a popular video on using a range rod, the indicator probe is excessively long for that type application.
D
Dennis Sorensen
Guest
By "out of round" do you mean the chamber is oval shaped or do you mean not concentric with the bore, or do you mean not concentric with the outside of the barrel?
How are you dialing in the barrel?
I didn't say "I want to use it" I said I think it's better.
your arguments are easily countered........
There is no clearance issue.... the rod is pressured against the side. If you put a concentric washer on the rod in lieu of a fitted bushing it would still be accurate. All you "measure" with a dial indicator is wobble. I guess if you did somehow get the rod fishing-poled into the throat area fully suspended then yes it would clank around like a slack drivetrain, but this could only happen through dumb luck and misapplication coupled with a low and tilted tailstock chuck. Properly applied the method relies on a 12"-16" long range rod, it's gonna' sag. The rod can be just chucked into a tailstock chuck and lifted into the bore
-And some guy's using a too cheesy indicator in some video??? So use a better indicator
-Who cares how long the indicator probe is? It's probably the same probe they guy USED to try use directly. I guess he should go buy a shorter one because the long probe is excessive? Howsabout he just chokes up on the probe? Is this misuse too?
We're not ALL retarded...... most of us aren't even liberals.... just making assertions and using the old "if you want to do it by all means don't let ME stop you" patronage doesn't make a case. Show mechanically how the method can be "less accurate" and I'm right there with you.
al
P
pwolfppc
Guest
I didn't say "I want to use it" I said I think it's better.
your arguments are easily countered........
--------------------------------
-And some guy's using a too cheesy indicator in some video??? So use a better indicator
-Who cares how long the indicator probe is?
---------------------------------------
We're not ALL retarded...... most of us aren't even liberals.... just making assertions and using the old "if you want to do it by all means don't let ME stop you" patronage doesn't make a case. Show mechanically how the method can be "less accurate" and I'm right there with you.
al
al, this has to be one of the rudest and most ill considered responses i've ever seen. i don't visit here often but i notice more and more the real benchrest shooters are posting less and less. no wonder when they have to put up with this type crap)chill()chill()chill
mad:al, this has to be one of the rudest and most ill considered responses i've ever seen. i don't visit here often but i notice more and more the real benchrest shooters are posting less and less. no wonder when they have to put up with this type crap)chill()chill()chill
Ahhhh Paul, so here it is in a nutshell..... "real benchresters" by your definition aren't requires to make a case, just to proclaim "how it is" and it is so.
Sorry guy, IMO Gordy Gritters is a "real benchrester" too. He even builds some "real benchrest rifles." I've watched people compare methods, squabble over methods, even (Lord Forbid) ARGUE over methods for lo these many years but now it's a status thing? You reach a certain level and you're above all that?
In this regard we seem to differ, at least our definition of "real benchresters" differs.
Sorry if I've peed in your Good Ol' Boy cheerios.
Translated, "not worth the bandwidth" most often means "I'd better pull out of this as it's not going so well." ((Of course the intended message is "this guy's just too stupid for me to spend time on
)) Rude??? nahhhhh, perfectly acceptable if you're a "real benchrester."
And I didn't even get to read the post.
If you think it's "rude" to disagree, to dispute or question the status quo, if you feel that there's some sort of mystical hierarchy of wisdom to respect, then an internet chat board probably isn't the best place to make your case. You gonna' talk down on someone or about someone in a crowded room you better have the seeds to stand up and prove your case. (Ohhh, and yes, maybe it's an East Coast/West Coast thing but there are many levels of rude and referring obliquely "a popular video" in a disparaging way is no more or less rude than naming names..... here in the West.)
All Jerry's succeeded in doing is advancing the opinion that Ol' Alinwa's just TOO DUMB to understand his explanation. (And inferring that those who DO embrace another method must be equally hampered.)
Will it fly? Are folks gonna' take sides and all that?
I sincerely hope not because Jerry's a perty smart feller. Gener'ly able to fight his own battles.
Sooo, is that it Jerry? Your position is that I'm incapable of understanding?
Hey, here's another one we disagree on Jerry...... you feel that aligning the entry and exit points of the barrel with the centerline of the rifle is more important than aligning the chamber to the entry point of the barrel....... and I see it differently. Oddly enough I even understand your argument, I just disagree.
But then I'm certainly not a "real benchrester."
al
P
pwolfppc
Guest
al, you just proved jerrys point, you are not worth the bandwidth. btw, my name is peter, not paul.
Sorry Peter, while this may "prove a point" to you it proves nothing in a discussion except that you're completely ignorant of (or ignoring) the actual question/contention.
Jerry wants to talk about tolerance stack..... and until someone shows him that tolerance stack IS NOT PART OF THE ISSUE the only "discussion" involves guys like you taking sides and making it into a fight. This isn't a fight.
Nor is it a popularity contest.
Jerry came on to point out something to me, something that he believes to be a problem. I understand his contention BUT I DISAGREE WITH IT. I think Jerry's missing a key point.
Or I'm wrong.
If, on reading this Jerry (or you) can point out where I've missed the boat then I'm wrong..... and I'll have learned something.
Tolerance stack would be an issue if the range rod were just rattling around in the bore, but it's not. It will always be pressured against one side of the bore..... just like the stylus on a conventional indicator.
Let's look at it another way..... let's forget about the bushing and use a range rod that's just a long indicator stylus. A 12" long stylus with a ball or knob riding the bore just like an indicator does, pressured lightly against the side of the bore. Now the reading indicator is mounted say 4" back from the end of the stylus and it rides with the tailstock. In essence you've turned the whole tailstock, indicator rod and dial indicator into one big dial indicator.
Does it work now? (I realize that in actuality this illustration is flawed because a 12" long indicator would tend to climb the lands and flex sideways, hence the roller tip, but I'm using it to draw the picture of the setup. )
Can you show me how there's a tolerance stack problem? The bushing fit to bore and even the fit of the bushing to the range rod aren't critical to the setup. In fact I believe that bushing fit to the bore should be loose to prevent binding in initial setup. The intent is not to try to eliminate slop or play or tolerance stack (impossible) but to give one the ability to accurately reach a depth that's impossible to achieve without the range rod. The best indicator I know of reads to a half thou at 2 3/4" depth..... and watching it bump over the lands while running it in and out gives my eyeball-to-brain interface a workout ...... but using this method you can gain a real sense of the bore curvature trend for the first 3" of the bore. With a range rod you can gain the same sense for 4" or 5" if you so choose.
Is checking for curvature important???
Different subject, and I dunno..... but if one DOES want to check it, it is my opinion that for finding bore direction trends it is hoovis to run the area fore and aft of the throat before starting the boring/reaming process.
Concerning the efficacy of "Gordy's Method" VS the more conventional method of indicating muzzle/breech/throat, I've recently tested two brand new barrels on custom actions which were chambered point-to-point and which shoot clear out of the scope at 100yds. One of them is on a 600yd Heavy gun that I'd like to shoot next Sat and I can't because I'm going to have to gouge out and rebed the rings to even get on paper......A crooked bore is a crooked bore and until someone comes up with a way to indicate the entire bore and offset to bring the muzzle into parallel, neither method guarantees you'll hit in the scope. Meantime, indexing to the vertical plane shore makes it easier to deal with whether it's more accurate or not. And if putting the muzzle directly "in front of" the chamber is important to accuracy, then that too is a big subject....
But I think the question concerns tolerance stack.
If the range rod is biased and not just clanking around in its' clearances..... is there still unacceptable tolerance in the system?
If the contention is that the rod climbs in its' bushing or that the bushing riding the tops of the lands is not acceptable then I'm barking up the wrong tree. MY question concerns only tolerance stack....... or the lack thereof.
How does a biased indicator rod have more tolerance than a biased stylus?
al
Jerry wants to talk about tolerance stack..... and until someone shows him that tolerance stack IS NOT PART OF THE ISSUE the only "discussion" involves guys like you taking sides and making it into a fight. This isn't a fight.
Nor is it a popularity contest.
Jerry came on to point out something to me, something that he believes to be a problem. I understand his contention BUT I DISAGREE WITH IT. I think Jerry's missing a key point.
Or I'm wrong.
If, on reading this Jerry (or you) can point out where I've missed the boat then I'm wrong..... and I'll have learned something.
Tolerance stack would be an issue if the range rod were just rattling around in the bore, but it's not. It will always be pressured against one side of the bore..... just like the stylus on a conventional indicator.
Let's look at it another way..... let's forget about the bushing and use a range rod that's just a long indicator stylus. A 12" long stylus with a ball or knob riding the bore just like an indicator does, pressured lightly against the side of the bore. Now the reading indicator is mounted say 4" back from the end of the stylus and it rides with the tailstock. In essence you've turned the whole tailstock, indicator rod and dial indicator into one big dial indicator.
Does it work now? (I realize that in actuality this illustration is flawed because a 12" long indicator would tend to climb the lands and flex sideways, hence the roller tip, but I'm using it to draw the picture of the setup. )
Can you show me how there's a tolerance stack problem? The bushing fit to bore and even the fit of the bushing to the range rod aren't critical to the setup. In fact I believe that bushing fit to the bore should be loose to prevent binding in initial setup. The intent is not to try to eliminate slop or play or tolerance stack (impossible) but to give one the ability to accurately reach a depth that's impossible to achieve without the range rod. The best indicator I know of reads to a half thou at 2 3/4" depth..... and watching it bump over the lands while running it in and out gives my eyeball-to-brain interface a workout
...... but using this method you can gain a real sense of the bore curvature trend for the first 3" of the bore. With a range rod you can gain the same sense for 4" or 5" if you so choose.Is checking for curvature important???
Different subject, and I dunno..... but if one DOES want to check it, it is my opinion that for finding bore direction trends it is hoovis to run the area fore and aft of the throat before starting the boring/reaming process.
Concerning the efficacy of "Gordy's Method" VS the more conventional method of indicating muzzle/breech/throat, I've recently tested two brand new barrels on custom actions which were chambered point-to-point and which shoot clear out of the scope at 100yds. One of them is on a 600yd Heavy gun that I'd like to shoot next Sat and I can't because I'm going to have to gouge out and rebed the rings to even get on paper......A crooked bore is a crooked bore and until someone comes up with a way to indicate the entire bore and offset to bring the muzzle into parallel, neither method guarantees you'll hit in the scope. Meantime, indexing to the vertical plane shore makes it easier to deal with whether it's more accurate or not. And if putting the muzzle directly "in front of" the chamber is important to accuracy, then that too is a big subject....
But I think the question concerns tolerance stack.
If the range rod is biased and not just clanking around in its' clearances..... is there still unacceptable tolerance in the system?
If the contention is that the rod climbs in its' bushing or that the bushing riding the tops of the lands is not acceptable then I'm barking up the wrong tree. MY question concerns only tolerance stack....... or the lack thereof.
How does a biased indicator rod have more tolerance than a biased stylus?
al
Boyd Allen
Active member
Hoping to to take a little of the heat from this thread, let me offer a link to a short video showing how Gordy sets up a barrel.
http://www.youtube.com/watch?v=aII2tbavKnM
If you follow it to the end, where there is a closeup of the indicator, you will see that it is one that reads directly to .0001", and judging by that and the length of the probe, I imagine that it is not a cheap one. It may be that the previous posters were referring to different videos, and did not realize it.
This rod is different from those previously offered, both in design, and how it is used. When I first saw the video, I was intrigued by the ingenuity of the design.
I recently had a conversation with a recent world record holder. He shared with me that another shooter who also belongs to that exclusive group, and who is a fine gunsmith, has changed over to the method shown in the video, because he thinks that it gives superior results.
Please, lets try to have these discussions with more light and less heat, something that I have admittedly sometimes failed to do myself.
http://www.youtube.com/watch?v=aII2tbavKnM
If you follow it to the end, where there is a closeup of the indicator, you will see that it is one that reads directly to .0001", and judging by that and the length of the probe, I imagine that it is not a cheap one. It may be that the previous posters were referring to different videos, and did not realize it.
This rod is different from those previously offered, both in design, and how it is used. When I first saw the video, I was intrigued by the ingenuity of the design.
I recently had a conversation with a recent world record holder. He shared with me that another shooter who also belongs to that exclusive group, and who is a fine gunsmith, has changed over to the method shown in the video, because he thinks that it gives superior results.
Please, lets try to have these discussions with more light and less heat, something that I have admittedly sometimes failed to do myself.
D
Dennis Sorensen
Guest
Good post Boyd, that is a really neat video...
Pictures make it so much easier...
Pictures make it so much easier...
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The one thing I'm working on that's DIFFERENT than Gordy's setup is to fasten the indicator to the tailstock so that it travels with the range rod instead of being off to the side. I'm embarrassed to show the massive hunk of angle iron clamped to the tailstock chuck but I think this makes Gordy's method even more sound. All I'm really doing is using the rod as a stylus extension. The angle iron mess also allows for two indicators set 90* to each other.
Incidentally, I see no reason for Gordy to be using the end of the stylus in the vid. He could choke it up and double the resolution.
I tried all this stuff using a pivoting bar years ago and just could not get rid of the slop even with springs but this range rod thing seems tight.
Until someone explains differently.
If I can find slop I'll have to start over.
al
but I think this makes Gordy's method even more sound. All I'm really doing is using the rod as a stylus extension. The angle iron mess also allows for two indicators set 90* to each other.Incidentally, I see no reason for Gordy to be using the end of the stylus in the vid. He could choke it up and double the resolution.
I tried all this stuff using a pivoting bar years ago and just could not get rid of the slop even with springs but this range rod thing seems tight.
Until someone explains differently.
If I can find slop I'll have to start over.
al
Niccolo M.
Member
Al Gordy’s Method Is Sound…
...and I use it now and feel confident that I’m leaving nothing on the table in the accuracy or workmanship departments. When I check my work if find that my chambers are round, less that .0001 run out (more on that later) and are on size. If there were any run out the camber would be oversize. I used to use range rods one for each caliber and two indicators. With that method the bushing is in the throat area of the barrel and the tapered rod centers at the breach face. You have several inches of rod sticking out and by putting one indicator near the breach face and one at the right end you can dial in the area of the barrel that you are concerned with. The real beauty of Gordy’s method is that you can check the area required for longer cartridges and I think that it is more accurate. Another great deal is that you can cover the entire range of calibers with only three rods; you still need a set of bushings in each caliber.
If you look closely at the Mitutoyo indicator in the video you will see that it is a .0001 model but has the 1.5 inch long stylus instead of the stock .70 length stylus. What this does is allow you to reach further into the longer chambers when you are done to check your work. The trade off is that the resolution is now .0002142 at the tip instead of .0001(I told you that there would be more on that later). If you want to judge me harshly look at it this way; if the indicator reads one half of a tenth it would be one tenth. I have double checked some of my chambers as far as I can reach with a Starrett .0001 indicator and have found them to be less than a tenth out. My tests revealed the modified Mitutoyo is still the best way to go for day to day chambering of match quality benchrest barrels and I use the very same indicator in my shop but hold it in a fixture in my Aloris tool post. The indicator that comes stock with the longer stylus is .0005 resolution and as far as I’m concerned has little use in this application. So yes you are correct if you choke up on the rod you will reduce the resolution.
It is only because of inquiring minds and people thinking that there has to be a better way that the shooting sports have reached the level of accuracy that we enjoy today and require to even finish in the front of the pack. I understand your concern over tolerance stacking but so far I have not found it to be a factor. If you really want to start a fight make a post pointing out that it is highly unlikely that anyone can chuck up a rifle barrel through the headstock, with both the breach and muzzle ends running true and not be bending the barrel between the chuck and spider.
I enjoy your posts,
Nic.
...and I use it now and feel confident that I’m leaving nothing on the table in the accuracy or workmanship departments. When I check my work if find that my chambers are round, less that .0001 run out (more on that later) and are on size. If there were any run out the camber would be oversize. I used to use range rods one for each caliber and two indicators. With that method the bushing is in the throat area of the barrel and the tapered rod centers at the breach face. You have several inches of rod sticking out and by putting one indicator near the breach face and one at the right end you can dial in the area of the barrel that you are concerned with. The real beauty of Gordy’s method is that you can check the area required for longer cartridges and I think that it is more accurate. Another great deal is that you can cover the entire range of calibers with only three rods; you still need a set of bushings in each caliber.
If you look closely at the Mitutoyo indicator in the video you will see that it is a .0001 model but has the 1.5 inch long stylus instead of the stock .70 length stylus. What this does is allow you to reach further into the longer chambers when you are done to check your work. The trade off is that the resolution is now .0002142 at the tip instead of .0001(I told you that there would be more on that later). If you want to judge me harshly look at it this way; if the indicator reads one half of a tenth it would be one tenth. I have double checked some of my chambers as far as I can reach with a Starrett .0001 indicator and have found them to be less than a tenth out. My tests revealed the modified Mitutoyo is still the best way to go for day to day chambering of match quality benchrest barrels and I use the very same indicator in my shop but hold it in a fixture in my Aloris tool post. The indicator that comes stock with the longer stylus is .0005 resolution and as far as I’m concerned has little use in this application. So yes you are correct if you choke up on the rod you will reduce the resolution.
It is only because of inquiring minds and people thinking that there has to be a better way that the shooting sports have reached the level of accuracy that we enjoy today and require to even finish in the front of the pack. I understand your concern over tolerance stacking but so far I have not found it to be a factor. If you really want to start a fight make a post pointing out that it is highly unlikely that anyone can chuck up a rifle barrel through the headstock, with both the breach and muzzle ends running true and not be bending the barrel between the chuck and spider.
I enjoy your posts,
Nic.
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Thanks Nic.
I've tried using 12ga and 10ga copper wire rings in the chuck and an assortment of 'L' shaped brackets like Gordy's using. I really like the brackets and feel comfortable that I don't bend barrels in setup.
Sure wish I had a Buck Chuck
al
K
Ken Worth
Guest
Couple of months ago I ask the question about barrel indicating;
http://www.benchrest.com/forums/showthread.php?t=65602
I never did get a feel for how a barrel is indexed in a glued in action, otherwise wouldn't it shoot way off if the muzzle runs out like the one I saw at the 2009 SHOT show? It was running out .06"-.08" or more.
Just using simple math, a 36" barrel out 0.6" on a 600 yard gun, it would be shooting off 36" at 600 yards.
http://www.benchrest.com/forums/showthread.php?t=65602
I never did get a feel for how a barrel is indexed in a glued in action, otherwise wouldn't it shoot way off if the muzzle runs out like the one I saw at the 2009 SHOT show? It was running out .06"-.08" or more.
Just using simple math, a 36" barrel out 0.6" on a 600 yard gun, it would be shooting off 36" at 600 yards.
P
pwolfppc
Guest
Couple of months ago I ask the question about barrel indicating;
http://www.benchrest.com/forums/showthread.php?t=65602
I never did get a feel for how a barrel is indexed in a glued in action, otherwise wouldn't it shoot way off if the muzzle runs out like the one I saw at the 2009 SHOT show? It was running out .06"-.08" or more.
Just using simple math, a 36" barrel out 0.6" on a 600 yard gun, it would be shooting off 36" at 600 yards.
Could someone who is a user of the range rod method please explain how they index to get the barrel pointing up or down?
For some reason this answer is being avoided according to Ken. I think we know this has to be done otherwise the gun will not track properly.