M
mike in co
Guest
me thinks the laser dot will be too large.......thier dots enlarge as the distance grows, and me thinks at 100 yds too big a target......
mike in co
mike in co
Secrets Of The Houston Warehouse
- Thread starter Louis.J
- Start date
Bob Kingsbury
New member
Knowing that scopes can also be an issue, how will you discern what is scope and what is action/ barrel movement ?
Boyd Allen
Active member
A related question:
Could Vaughn have been looking at a stress relief issue, and incorrectly identified it as a barrel to receiver joint issue? (given the rifle that he was using for his test) I seem to remember accounts that would indicate that well made cut rifled sporter weight barrels having less of a tendency to loose accuracy as they heat up. There is also the issue of unbalanced cooling of very hot barrels, because of typical stock designs.
Could Vaughn have been looking at a stress relief issue, and incorrectly identified it as a barrel to receiver joint issue? (given the rifle that he was using for his test) I seem to remember accounts that would indicate that well made cut rifled sporter weight barrels having less of a tendency to loose accuracy as they heat up. There is also the issue of unbalanced cooling of very hot barrels, because of typical stock designs.
Bob Kingsbury
New member
Charles,,
I could be wrong here, but I think it was Harold Vaughn that said the threaded barrel joint allowed the scope
and barrel to change direction relative to each other. That has been the subject of the most recent posts here.
It should be noted, that he was in fact testing a 270 factory installed barrel which we would recognize as likely
flawed in typical ways. I have long felt the shoulder is as important as the chamber. Having seen way to many
shoulders that were cut with parting tools on poor shooting rifles, I take extra care in cutting square and flat shoulders.
I am not speaking of .350 guns, but rather the .200 gun that refuses to improve. In that respect, Its hard to believe
that a laser would define it very well.
I could be wrong here, but I think it was Harold Vaughn that said the threaded barrel joint allowed the scope
and barrel to change direction relative to each other. That has been the subject of the most recent posts here.
It should be noted, that he was in fact testing a 270 factory installed barrel which we would recognize as likely
flawed in typical ways. I have long felt the shoulder is as important as the chamber. Having seen way to many
shoulders that were cut with parting tools on poor shooting rifles, I take extra care in cutting square and flat shoulders.
I am not speaking of .350 guns, but rather the .200 gun that refuses to improve. In that respect, Its hard to believe
that a laser would define it very well.
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4Mesh
Guest
The very fact that you would suggest using them tells me that you are aware they work and how, and even when placed over bore only. Well then how much "testing and proof" do you need to understand that the barrel joint with double the internal surface and half the surrounding metal, does the same stretching and moving?Bob Kingsbury said:
Bob, a very thin coat of Dykem on the reciever face works to check this. I've seen one rifle 'cured' after this confirmed poor barrel to reciever face contact.
Good shootin'. -Al
Bob Kingsbury
New member
AL
Thanks AL, actually I do this as a matter of SOP. I have even gone to the lengths of grinding hardened laps, used
with diamond to flatten receiver faces which are sleeved and assembled years ago before action truing became common.
4Mesh,
I have no doubt that the barrel/action conection moves. Anything short of one solid piece of metal will given
the heat and shock we subject them to. There are some guns however that we refer to as hummers, that may
almost show an imunity to this. I think we can both agree that not all the guns on the line are capable of
being winners, some are better, and some just make noise.
Thanks AL, actually I do this as a matter of SOP. I have even gone to the lengths of grinding hardened laps, used
with diamond to flatten receiver faces which are sleeved and assembled years ago before action truing became common.
4Mesh,
I have no doubt that the barrel/action conection moves. Anything short of one solid piece of metal will given
the heat and shock we subject them to. There are some guns however that we refer to as hummers, that may
almost show an imunity to this. I think we can both agree that not all the guns on the line are capable of
being winners, some are better, and some just make noise.
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4Mesh
Guest
Well,
the thing I have the trouble with is any of us thinking some of these problems have been solved, just cause we fixed them part way. Yea, new custom actions address a lot of the movement issues. But then people start thinking like many in this thread that because the problem isn't screaming at them saying "Hello, I'm here", that means it isn't there. I don't think there will ever be a total solution to the barrel joint problem. Not one commercially feasible to produce anyway.
It's my opinion that many of the mechanical issues with match rifles (any discipline) have had problems that I'll call a 1"@100 problem that was "Fixed" and made into a .1"@100 problem. So then people start thinking that problem is fixed when in fact, it will simply have to wait till that .1" problem starts gett'n guys beat before they get off their duffs and go fix it.
jmho.
the thing I have the trouble with is any of us thinking some of these problems have been solved, just cause we fixed them part way. Yea, new custom actions address a lot of the movement issues. But then people start thinking like many in this thread that because the problem isn't screaming at them saying "Hello, I'm here", that means it isn't there. I don't think there will ever be a total solution to the barrel joint problem. Not one commercially feasible to produce anyway.
It's my opinion that many of the mechanical issues with match rifles (any discipline) have had problems that I'll call a 1"@100 problem that was "Fixed" and made into a .1"@100 problem. So then people start thinking that problem is fixed when in fact, it will simply have to wait till that .1" problem starts gett'n guys beat before they get off their duffs and go fix it.
jmho.
M
mks
Guest
You could use two lasers, one on the barrel and one on the action.
M
mks
Guest
Could be just fine for long range rifles with long barrels. For short barrels, the barrel block could be a disadvantage for barrel vibration. The effectively shorter barrel (distance from the block to the muzzle) would tend to speed up the vibration response, pushing bullet exit time to the downward part of the muzzle angle curve, when we want it to be on the upward slope. A heavy tuner might compensate for this effect.
Cheers,
Keith
Boyd Allen
Active member
He tested with a stock (crooked) Remington 721 in .270, in a rest that prevented the rifle from rising as it recoiled (I think.). If you hold the action down, doesn't that put more stress on the barrel to receiver joint? Also, would not factory fit be less resistant to movement? Also did anyone notice that even after it dropped to a lower value after firing that a "variable depth thread" was able to slightly exceed his minimum axial preload requirement for a stable joint? Perhaps we are making this too difficult.
Boyd Allen
Active member
Charles,
If one does not first establish that there is barrel joint motion when firing a particular rifle, it would seem that there is no way to know why the rifle shoots better when a block is added. Vaughn used a machine rest, and a scope on a mandrel to demonstrate that there was a joint problem in his rifle, but as to the probability of those results implying a similar problem in short range benchrest rifles he wrote, "Bench rest rifles have heavy barrels which conduct the heat away from the barrel joint reducing the effect of temperature. Also the heavy barrel helps the load on the joint. These features coupled with the fact that smaller calibers are usually used, and barrels are cleaned frequently allowing the temperature differential to equalize, reduce the probability of barrel joint motion on bench rest rifles." Another thing that I find interesting is that while He takes pains to describe how careful he is with his barreling, no where do I remember reading of his blueprinting the action. I also found his approach to improving lug engagement somewhat novel, and his high regard for "O'Connor bedding" is interesting. I have a friend that has a rather stout, single shot hunting rifle chambered in a slightly modified (shoulder angle) .338 Lapua. In his meticulous target record book contains one target that measures slightly under one quarter inch (5 shots). I have seen him shoot the rifle, and that target. It is a switch barrel rifle, and he uses a normal barrel tightening procedure. Evidently barrel movement issues in non blocked heavy caliber rifles are not universal.
If one does not first establish that there is barrel joint motion when firing a particular rifle, it would seem that there is no way to know why the rifle shoots better when a block is added. Vaughn used a machine rest, and a scope on a mandrel to demonstrate that there was a joint problem in his rifle, but as to the probability of those results implying a similar problem in short range benchrest rifles he wrote, "Bench rest rifles have heavy barrels which conduct the heat away from the barrel joint reducing the effect of temperature. Also the heavy barrel helps the load on the joint. These features coupled with the fact that smaller calibers are usually used, and barrels are cleaned frequently allowing the temperature differential to equalize, reduce the probability of barrel joint motion on bench rest rifles." Another thing that I find interesting is that while He takes pains to describe how careful he is with his barreling, no where do I remember reading of his blueprinting the action. I also found his approach to improving lug engagement somewhat novel, and his high regard for "O'Connor bedding" is interesting. I have a friend that has a rather stout, single shot hunting rifle chambered in a slightly modified (shoulder angle) .338 Lapua. In his meticulous target record book contains one target that measures slightly under one quarter inch (5 shots). I have seen him shoot the rifle, and that target. It is a switch barrel rifle, and he uses a normal barrel tightening procedure. Evidently barrel movement issues in non blocked heavy caliber rifles are not universal.
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4Mesh
Guest
Boyd,
Lots of stuff in that book in one way or another relate to the mechanical imperfections of his actions causing issues, what issues, how big they are and how to avoid them. That's what blueprinting an action is all about. He simply went about it differently. His squaring the lugs process was an entire chapter iirc.
You write that your buddy's 338L demonstrates that movement may not be universally present, yet, how many of those 1/4" targets did that thing shoot? By what I read, it shot one. 1. Uno... What do you suppose is happening the rest of the time? Maybe somethin' movin?
Lots of stuff in that book in one way or another relate to the mechanical imperfections of his actions causing issues, what issues, how big they are and how to avoid them. That's what blueprinting an action is all about. He simply went about it differently. His squaring the lugs process was an entire chapter iirc.
You write that your buddy's 338L demonstrates that movement may not be universally present, yet, how many of those 1/4" targets did that thing shoot? By what I read, it shot one. 1. Uno... What do you suppose is happening the rest of the time? Maybe somethin' movin?
M
mks
Guest
Interesting. What was your ES? Barrel vibration is irrelevant is ES is small. Or maybe your rifle had "good vibrations" in spite of my concerns. Actually, barrel vibration effects are relatively small at short range anyway. But if we are looking for the next incremental improvement, all of this stuff is fair game.
As Boyd said, Vaughn measured barrel/receiver motion with two scopes. Flyers occurred the shot after the motion was measured. After rereading his Chap. 6, I have no doubt that it happened in his rifle. Seems like I have at least a couple (and sometimes a boatload) of flyers every match. Absent measurements to the contrary, this is as good an explanation as any.
Boyd Allen
Active member
It is very consistent (and yes, that was his best target), it is just that given the weight of the rifle, and the recoil level, and the difficulty in executing perfect shots at that level, I would not loose much sleep over barrel to action motion as being the probable cause of errors. It would seem that some are willing to take a specific test, and generalize broadly, without doing any testing of other rifles to see if they actually have the problem. This approach has the advantage of requiring no additional work or expenditure, simply making a declaration. From Vaughn we know that his barrel joint moved and it is highly probable that under the same conditions others will also. What we don't know is how much the test apparatus affected the outcome, or whether a specific rifle, that has not been tested, has the problem. On the other hand, I am a great believer in the validity of results obtained by cut and try on a particular rifle, even though we may only be guessing as to why "it" worked.
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4Mesh
Guest
And if I thought that there was another error that was bigger, I'd fry that fish first too. But when the time came that I was tired of making excuses for all that stuff I didn't want to work at finding, I'd start looking harder for that stuff that wasn't easy to fix. If I didn't believe something had any effects upon the rifle, I'd look elsewhere. I guess that's where we differ on this.
I would agree that generalization is bad, and assuming without any testing could also be bad. But if you were implying that I've made assumptions on this without any testing, I'm not sure you could be any more wrong.
We all guess as to why things work, but not forever.
Boyd Allen
Active member
Have you done something to specifically prove barrel joint movement on one of your rifles...with a fixture, like Vaughn did?
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4Mesh
Guest
Vaughn didn't do that because he wanted to know IF there was movement, he did it because for the sake of the book he needed to quantify how much. I never wrote a book, so quantifying wasn't on my agenda. I resolved the problem to the best of my ability, and I am reasonably sure there is more yet to fix. jmo.
Boyd Allen
Active member
Just to be clear, I think that all progress is good, even if the work that leads to it fails to meet scientific standards, which my problem solving almost never does, and if you have improved the integrity of your barrel to action joints, I only need to know one thing....how is it done?
Boyd, I may have it all wrong, But I don't see that.Just to be clear, I think that all progress is good, even if the work that leads to it fails to meet scientific standards, which my problem solving almost never does, and if you have improved the integrity of your barrel to action joints, I only need to know one thing....how is it done?
When I posted what I thought a solution, your answer was along the lines of "Well, it isn't a problem anyway." With Vaughn, someone who had done the math, both for the potential problem and the typical assembly & materials, you questioned his action truing or quality of barrel.
Since no answer could be acceptable, I pulled all my recent posts on this thread.
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