Controlling and adjusting runout - concentricity
- Thread starter Martyk
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I secure the die to the press after sizing a case, I raise the ram, the case resistance to being sized raises the die, or, removes the slack between the threads of the press and die, when the slack is removed, I secure the die with the lock nut, there is nothing that will overcome misalignment when the thread size is 7/8 x 14 tpi.
Another technique, install the die, raise the ram, adjust the die down to the shell holder until it makes contact, lower the ram, lower the die an additional 1/8 turn, .007 thousands, put the press in a bind by raising the ram then secure the nut, If then you want to know if the die, shell holder, press and ram is in perfect alignment purchase a feeler gage and use it to determine if there are gaps between the shell holder and die, remember, if the press is in a bind the tweak of the press will assure 100% contact between the die and shell holder.
Chasing run-out, I do not go to the range with one 30/06, or one 8X57 etc., there are times I take 4 30/06 rifles, one will shoot 1 inch groups another will shoot 3 inch groups etc all with the same ammo, I have taken two 300Win mags, one shots a one hole group with three rounds, the other shots a group that is better desccribed as a pattern.Sizer ball problems are created by the reloader, in the perfect world cases are new or once fired, the ability of the brass to be size changes, the reloaders perception of sizing doesn't, the fact the sizer ball makes a loud screech and is difficult to pull back through the neck does not tell the reloader anything, the noise and resaistance to sizing is always attributed to lube or the reloader creates another problem by making the sizer ball easier to pass through the neck by reducing the diameter.
Neck size first without the sizer then install the sizer and size again? That sounds like necking down then necking up, necking down and necking up again, to me that sounds like excelerated hardening of brass without firing, When brass is manufactured it is annealed as many as 5 times, back to the perfect world of brass, my brass does not have an exemption, I size, shoot, size, shoot etc.,sizing and shooting changes the nature of brass, my brass, when I size a case and hear the sizer ball/neck expander being pulled through the neck and it is difficult to bull through I know the brass is work hardened.
Pulling the sizer ball through the neck on worked hardened brass can stretch the brass, this is not a functrion of the neck expander, the neck should shorten when the expander is pulled through, it is sort of a trade off, when the neck is sized down it gets longer, there are times when claims are made the neck gets thicker when necked down and thinner when necked up, by those that that have not measured the case length fefore, during and after.
In the perfect world the case would be supported when seating bullets, seating a bullet can squat the case, reducing the diameter of the expander/neck sizer ball can increase bullet seating effort.
F. Guffey
Another technique, install the die, raise the ram, adjust the die down to the shell holder until it makes contact, lower the ram, lower the die an additional 1/8 turn, .007 thousands, put the press in a bind by raising the ram then secure the nut, If then you want to know if the die, shell holder, press and ram is in perfect alignment purchase a feeler gage and use it to determine if there are gaps between the shell holder and die, remember, if the press is in a bind the tweak of the press will assure 100% contact between the die and shell holder.
Chasing run-out, I do not go to the range with one 30/06, or one 8X57 etc., there are times I take 4 30/06 rifles, one will shoot 1 inch groups another will shoot 3 inch groups etc all with the same ammo, I have taken two 300Win mags, one shots a one hole group with three rounds, the other shots a group that is better desccribed as a pattern.Sizer ball problems are created by the reloader, in the perfect world cases are new or once fired, the ability of the brass to be size changes, the reloaders perception of sizing doesn't, the fact the sizer ball makes a loud screech and is difficult to pull back through the neck does not tell the reloader anything, the noise and resaistance to sizing is always attributed to lube or the reloader creates another problem by making the sizer ball easier to pass through the neck by reducing the diameter.
Neck size first without the sizer then install the sizer and size again? That sounds like necking down then necking up, necking down and necking up again, to me that sounds like excelerated hardening of brass without firing, When brass is manufactured it is annealed as many as 5 times, back to the perfect world of brass, my brass does not have an exemption, I size, shoot, size, shoot etc.,sizing and shooting changes the nature of brass, my brass, when I size a case and hear the sizer ball/neck expander being pulled through the neck and it is difficult to bull through I know the brass is work hardened.
Pulling the sizer ball through the neck on worked hardened brass can stretch the brass, this is not a functrion of the neck expander, the neck should shorten when the expander is pulled through, it is sort of a trade off, when the neck is sized down it gets longer, there are times when claims are made the neck gets thicker when necked down and thinner when necked up, by those that that have not measured the case length fefore, during and after.
In the perfect world the case would be supported when seating bullets, seating a bullet can squat the case, reducing the diameter of the expander/neck sizer ball can increase bullet seating effort.
F. Guffey
pocketchange
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seating clearance
I tend to increase with larger calibers... not much but enough to not have a handing concern when moving from here to there.
I tend to increase with larger calibers... not much but enough to not have a handing concern when moving from here to there.
Dave P
Member
Bart - you index on the sloped shoulder?? "and another V at about midpoint on the shoulder"
I have spent countless hours preping brass and cartridges. I contend that 99% of us that shoot with iron sights should not worry about concentricity, (or spend much time at all when reloading). I proved this to myself again this weekend: threw together a known good load for 600 yards in my AR. Didn't even weigh the powder. Used a Lee hand press to seat bullets. Scored 196-6X (only dropped 4 points out of 200).
I have spent countless hours preping brass and cartridges. I contend that 99% of us that shoot with iron sights should not worry about concentricity, (or spend much time at all when reloading). I proved this to myself again this weekend: threw together a known good load for 600 yards in my AR. Didn't even weigh the powder. Used a Lee hand press to seat bullets. Scored 196-6X (only dropped 4 points out of 200).
Clark
Member
I have a Sinclair concentricity gauge.
One could skip buying it, if they just throw all expander balls away. Or just use them when needed, on a separate push stroke, and no deeper than needed.
But I have done some comparing:
Lee RGB dies
Lee collet neck dies
RCBS dies
Forster dies
Factory neck lapped Forster dies.
Redding FL "S" dies
1) A real surprise was the Lee Collet dies. They had been on the shelf for years collecting dust, because they looked cheap. They are also very good about keeping case lengths from growing fast with high pressure.
2) No surprise, the Forster sliding sleeve seater die is very good.
3) Another surprise is the quality of brass effect on concentricity of loaded ammo.
Lapua is good.
RP 6mmBR is good.
4) Bushing dies are bad for big changes in neck size.
5) Once a neck is bent, just about the only way to fix it, is to fire it.
6) The best I can do is a factory lapped and stress relieved barrel that is reamed with a custom reamer that is a tight no-turn neck.
7) The best I can do is only resize the neck inside diameters to .002" smaller than the bullet, with a lapped sizer die.
8) Concentricity has less effect than a few mph wind.
One could skip buying it, if they just throw all expander balls away. Or just use them when needed, on a separate push stroke, and no deeper than needed.
But I have done some comparing:
Lee RGB dies
Lee collet neck dies
RCBS dies
Forster dies
Factory neck lapped Forster dies.
Redding FL "S" dies
1) A real surprise was the Lee Collet dies. They had been on the shelf for years collecting dust, because they looked cheap. They are also very good about keeping case lengths from growing fast with high pressure.
2) No surprise, the Forster sliding sleeve seater die is very good.
3) Another surprise is the quality of brass effect on concentricity of loaded ammo.
Lapua is good.
RP 6mmBR is good.
4) Bushing dies are bad for big changes in neck size.
5) Once a neck is bent, just about the only way to fix it, is to fire it.
6) The best I can do is a factory lapped and stress relieved barrel that is reamed with a custom reamer that is a tight no-turn neck.
7) The best I can do is only resize the neck inside diameters to .002" smaller than the bullet, with a lapped sizer die.
8) Concentricity has less effect than a few mph wind.
something vague
Member
+2 on that, within reason of course.
counterclockwise
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.001 neck tension (.001 interference fit on the diameter) when you think about is very difficult to control. What is the tolerance or accuracy you are going to hold to attain that kind of a precision fit? I think you would have to hold +/-.0005 or better.
Maybe the more practical approach would be to set up for an interference fit that guarantees a maximum neck tension developed, eg. a fit that expands the brass beyond its elastic limit when the bullet is inserted, but does not exceed the ultimate stress.
Maybe the more practical approach would be to set up for an interference fit that guarantees a maximum neck tension developed, eg. a fit that expands the brass beyond its elastic limit when the bullet is inserted, but does not exceed the ultimate stress.
Gun Geezer
Member
I have no idea what you guys are talking about.
Been loading pistol ammo for years, but never rifle. Just don't shoot it enough. When I do, I'll try to figure this out. Or just buy the ammo!
Been loading pistol ammo for years, but never rifle. Just don't shoot it enough. When I do, I'll try to figure this out. Or just buy the ammo!
USSR
Member
Actually, .001" neck tension is easier to control than heavy neck tension. While you may have no idea if you have .003" or .004" of neck tension, it is quite obvious whether you have .000" or .001" of neck tension. Also, empirical data tends to support the fact that low neck tension (combined with other precision loading methods) usually produce the most accurate ammo.
Don
counterclockwise
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Please explain...
.
How do you validate that you are holding .001 +/-.000? neck tension, before you fire the round?
.
How do you validate that you are holding .001 +/-.000? neck tension, before you fire the round?
Last edited:
USSR
Member
We don't know for sure that it's exactly .001" of neck tension, but if it's much less than that, the bullet is loose in the neck, and you get a "feel" for when a bullet is seating a bit harder than expected.
Don
The best way I have found to monitor bullet grip is with a set of pin gauges
It's true that they are made in .001" incremental diameter but you can feel whether it is a tight fit or loose and make some judgements based on that. The pin gauge will also identify do-nuts and identify a narrowing at one end of the neck or the other. There can be dfferent causes for this like thickness variations and inside neck cleanliness.
IMO, controlling the surface at the inside of the neck and bullet grip is just as important as runout. Coating with mica can help stabilize seating pressure and thus OAL
It's true that they are made in .001" incremental diameter but you can feel whether it is a tight fit or loose and make some judgements based on that. The pin gauge will also identify do-nuts and identify a narrowing at one end of the neck or the other. There can be dfferent causes for this like thickness variations and inside neck cleanliness.
IMO, controlling the surface at the inside of the neck and bullet grip is just as important as runout. Coating with mica can help stabilize seating pressure and thus OAL
USSR
Member
Extremely reasonable. Thanks for the link, woods.
Don
Don
counterclockwise
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Walkalong
Oh, I thought you were referring to those beautiful mica-lined cases.
So, with those pin gages and a good 4 place micrometer, you should be able to map the .001 interference on the diameter good enough.
Woods, have you tried this: Insert a bullet, remove the bullet, re-gage the neck...to see if the .001 interference fit returns fully.
Oh, I thought you were referring to those beautiful mica-lined cases.
So, with those pin gages and a good 4 place micrometer, you should be able to map the .001 interference on the diameter good enough.
Woods, have you tried this: Insert a bullet, remove the bullet, re-gage the neck...to see if the .001 interference fit returns fully.
something vague
Member
Nice, thanks for the link. That's perfect set of tools for this purpose and reasonably priced. I also produce much better results with ~.001"-.0015" of neck tension.
Dave P, you asked:
I use these points as they're the ones that most of the case contacts the chamber at, either new or full length sized cases (and all variants of neck sized ones, too, probably)when the round's fired. And because I shoot only new or full length sized cases for best accuracy. Case shoulder's are pressed hard against the chamber shoulder and the extractor's pushing the case at right angles to the chamber axis so the pressure ring's touching the chamber wall opposite the closed-bolt position of the extractor when the round fires. I've also used a 3/8ths inch inside diameter nylon washer to support the shoulder of 30 caliber cases with the pressure ring resting on a nylon V block or two bearings. Supporting the front of the case midpoint on the shoulder eliminates any dimensional out of round the body has immediately behind the shoulder caused by varying body wall thickness around the case at that point. Whatever out of round there is at the pressure ring (and there sure is some 'cause body wall thickness there ain't uniform either.
Regarding all the issues about 1/1000ths inch of neck tension, that means different things to different people. Sizing a fired case neck by any means that ends up leaving the case mouth 1/1000th of an inch smaller than bullet diameter is 1/1000ths inch of neck tension to me. I don't care what the dimensions of the die's parts, bullet or neck wall thickness/hardness are to start with; it's only what one ends up with that's important as far as I'm concerned as that's what puts the tension on the bullet creating some level of release force needed to move the bullet out of the case.
Not quite. One V's about midpoint on the shoulder and the other's on the pressure ring. The pressure ring's typically about 2/10ths of an inch in front of the head on most rimless bottleneck cases.
I use these points as they're the ones that most of the case contacts the chamber at, either new or full length sized cases (and all variants of neck sized ones, too, probably)when the round's fired. And because I shoot only new or full length sized cases for best accuracy. Case shoulder's are pressed hard against the chamber shoulder and the extractor's pushing the case at right angles to the chamber axis so the pressure ring's touching the chamber wall opposite the closed-bolt position of the extractor when the round fires. I've also used a 3/8ths inch inside diameter nylon washer to support the shoulder of 30 caliber cases with the pressure ring resting on a nylon V block or two bearings. Supporting the front of the case midpoint on the shoulder eliminates any dimensional out of round the body has immediately behind the shoulder caused by varying body wall thickness around the case at that point. Whatever out of round there is at the pressure ring (and there sure is some 'cause body wall thickness there ain't uniform either.
Regarding all the issues about 1/1000ths inch of neck tension, that means different things to different people. Sizing a fired case neck by any means that ends up leaving the case mouth 1/1000th of an inch smaller than bullet diameter is 1/1000ths inch of neck tension to me. I don't care what the dimensions of the die's parts, bullet or neck wall thickness/hardness are to start with; it's only what one ends up with that's important as far as I'm concerned as that's what puts the tension on the bullet creating some level of release force needed to move the bullet out of the case.
counterclockwise, you stirred my interest. But I expanded the test a little. I have 3 different sized mandrels from Lee for my Lee Collet in 6.5 rem mag. Also thought it would be interesting to see if there was a difference between a 5 times fired case and a 1 time fired case
See if I can put it in a chart of sorts
mandrel size / # fired case / sized case pin size / pulled bullet pin size
.262" mandrel / 5 times fired / .263" / .263"
.262" mandrel / 1 time fired / .262" / .263"
------------------------------------------------
.261" mandrel / 5 times fired / .261" / .263"
.261" mandrel / 1 time fired / .261" / .263"
------------------------------------------------
.260" mandrel / 5 times fired / .260" / .263"
.260" mandrel / 5 times fired / .260" / .263"
I guess the thing to notice is that in every case, the case returned to .263" after the bullet was seated and pulled.
It would probably have been more informative if the pins came in .0001" increments, if they could be manufactured at all.
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