Has anybody tested Salazar's O-ring theory? It seems logical, but so do many other things.
thanks,
Rich
thanks,
Rich
The O-ring test...
- Thread starter IdahoSharpshooter
- Start date
If you are referring to putting an o-ring under the lock collar on your die, causing it to "float" in the press, it worked for me on a Hornady progressive press I owned a few years ago.
I do it. It's reduced about .001 of TIR on my Dillon 650 with .308 brass
Joe R
Gold $$ Contributor
FYI, the Hornady presses that using bushings all have O rings and they work well for me.
Joe
long40shot
Gold $$ Contributor
Can someone post a link to the article about this? I've not heard about it.
A quote from German Salazar from the article:
"You will probably see a slight improvement in neck concentricity as the die can now float a bit as the case enters and leaves it. This isn't going to be a dramatic improvement, but is a positive one".
O rings are used to keep the thread tight in the dies with out them . Your dies will have some movement . I like pinch type lock rings
But I use a press that the die floats to find the center . Many of presses the ram doesn't run straight to the center of the die thread. If that is happing the case will have press on the side . Larry
But I use a press that the die floats to find the center . Many of presses the ram doesn't run straight to the center of the die thread. If that is happing the case will have press on the side . Larry
The O-ring allows the die to float, Larry.
jepp2
Gold $$ Contributor
Yes, I use O-rings under all my sizing dies. But I use them for slightly different reasons, and I found larger contributors to case necks having runout.
I use the O-rings now because it make very small adjustments to the die possible during setup, that I can't get without the O-ring. If I tighten the set screw on Redding type lock rings, it makes the ring very hard to turn on the die body on future adjustments. On split type lock rings, if you tighten it with it against the press top, then it makes removing the die very difficult. And with the O-ring, my die body doesn't move during use - ever!
I found the largest cause of case neck runout when using a FL sizing die, was making the expander work too much. Typical standard FL sizing dies undersize the case neck around 3-6 thousandths. Even when using a carbide expander and very good lube inside the case neck, you lose neck concentricity when the expander comes back through the neck. I hone my die necks so the expander only has to increase the case neck from 0.0005 to 0.001". With that setup, my necks always have less than 0.001 TIR. But I also set the expander very high, so it passes through the case neck "just" as the neck leaves the neck sizing portion of the die body. This way the case is better supported by the die body. And yes, this means I have to deprime prior to sizing. With the expander set this high, it will not remove the primer.
The funny thing was when I first encountered the Lee die lock rings with the O-ring, I hated them. But I view that totally different now.
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BoydAllen
Gold $$ Contributor
I am always amazed that some seem to want multiple published verification of something that they could easily determine for themselves, by doing an easy to perform experiment. All that is required is an O ring, and a concentricity gauge. Yes, it works.
Years ago, after I explained how some something relating to reloading works to a friend, carefully and in detail, something that was not generally found in the available literature at the time that I had figured out on my own, he asked me what my reference was. It was as if for him it had to be written on a page to be valid. I have done a little accuracy related writhing in my time and know that putting something on a page does not make it true. I am always amazed that people do not seem to have the ability to come to their own conclusions based on their own careful work. Back before there were shooting sites on the internet, before there was an internet, the way that I learned some of the finer points was by figuring out myself, or learning them from someone who was at a higher level in our hobby, and solving the little problems that came up was one of the satisfying parts of the the game.
Some advice: You cannot fix what you cannot see. Get a concentricity gauge, and start using it on a regular basis to measure what your tools and techniques are producing. When you find a problem, do some experiments to try to fix it. You might succeed, and you might enjoy the process.
Years ago, I built a setup that allowed the die complete freedom to float in the presses threads without rotating in them. I tested several dies in various calibers to see whether it gave better runout. Some did, and some didn't. Some gave better results locked down. Many years later, I had a friend check and correct the perpendicularity of some lock rings' faces to their threads, using his lathe and a mandrel that had been threaded and left in the chuck for the whole process. They were not perfect. If I ever get a lathe of my own, one of the experiments that I want to do is to check how true the interiors of dies are to their threads.
Years ago, after I explained how some something relating to reloading works to a friend, carefully and in detail, something that was not generally found in the available literature at the time that I had figured out on my own, he asked me what my reference was. It was as if for him it had to be written on a page to be valid. I have done a little accuracy related writhing in my time and know that putting something on a page does not make it true. I am always amazed that people do not seem to have the ability to come to their own conclusions based on their own careful work. Back before there were shooting sites on the internet, before there was an internet, the way that I learned some of the finer points was by figuring out myself, or learning them from someone who was at a higher level in our hobby, and solving the little problems that came up was one of the satisfying parts of the the game.
Some advice: You cannot fix what you cannot see. Get a concentricity gauge, and start using it on a regular basis to measure what your tools and techniques are producing. When you find a problem, do some experiments to try to fix it. You might succeed, and you might enjoy the process.
Years ago, I built a setup that allowed the die complete freedom to float in the presses threads without rotating in them. I tested several dies in various calibers to see whether it gave better runout. Some did, and some didn't. Some gave better results locked down. Many years later, I had a friend check and correct the perpendicularity of some lock rings' faces to their threads, using his lathe and a mandrel that had been threaded and left in the chuck for the whole process. They were not perfect. If I ever get a lathe of my own, one of the experiments that I want to do is to check how true the interiors of dies are to their threads.
One example is elastic rebound when force is applied/released.
Your not putting any force on the o ring
The o ring is above the treads in the press .
Is is just pulling the thread to make them tight . Yes they do make adjust a die easy .
As soon as the die has pressure on it the thread along their self . Any thing above the threads in the press doesn't do anything . Pressure aligns the thread .
70 year I have been twisting wrenches and is hasnt change till now . O rings just apply Tension to help Keep the threads movement To a minimum . A jam nut is used. In automotive. For the same reason.
Floating shell holder or floating dies is the only way I see for a case to center its self
Larry
When you turn the lock ring against the O-ring you are putting force against the O-ring. If you want the die to float and help the alignment, use an O-ring. If you want to tighten the thread fit between the die threads and press threads, use teflon tape. If you want the die lock-ring to sit completely flat and flush with the top of the press, make an open end hillside washer from thin shim stock. Some people are so old fashioned, refuse to accept modern technology, and deny advancement.
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I've used German's advice. The float provided by the o-ring has improved concentricity for me. However, since the o-ring is compressible its difficult to duplicate shoulder bump precisely from one reloading session to the next. If you're willing to do a little fiddling with die adjustment it will most likely work for you as it did for me...................But I must say the small improvements in measured concentricity showed up on the dial indicator and NOT on target. Then again I'm NOT a top tier BR shooter. .................. If you're working with semi-auto cases which are subject to dings and dents in the extractor groove you'll probably get more benefit from an o-ring placed on the press ram to allow float of the shell holder. Just my experience.
BoydAllen
Gold $$ Contributor
Larry,
You are imagining instead of testing. I have done the testing, and no the purpose of the O ring is not the same as a lock nut. The O ring prevents the die from rotating while at the same time giving it the freedom to square itself to the press's threads. That is not what a lock nut is used for. Given how loose dies generally fit in press threads, it is possible to lock one down so that it is slightly cocked. That is why, going back a long time, there has been some reference in the literature to squaring a die to the shell holder before tightening the lock ring. I have done the actual test. I have also used the Lee lock ring and found small improvement in case concentricity. The question is whether the differences show up on the target. Beyond a certain point I am not sure that they do.
You are imagining instead of testing. I have done the testing, and no the purpose of the O ring is not the same as a lock nut. The O ring prevents the die from rotating while at the same time giving it the freedom to square itself to the press's threads. That is not what a lock nut is used for. Given how loose dies generally fit in press threads, it is possible to lock one down so that it is slightly cocked. That is why, going back a long time, there has been some reference in the literature to squaring a die to the shell holder before tightening the lock ring. I have done the actual test. I have also used the Lee lock ring and found small improvement in case concentricity. The question is whether the differences show up on the target. Beyond a certain point I am not sure that they do.
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