I recently borrowed a friends ICC testing machine and checked several brands of 6mm bullets and sorted many of them. I still haven't tested them on a target, but plan on taking the worst of a lot and the best to compare soon. I have read quite a bit of slightly older posts about the instrument and there seems to be a lot of questions about what the machine is actually doing. I guess it is measuring the thickness of the copper jacket for concentricity, but a solid copper bullet will read quite a big spread as it is rotated. Even a solid pin like a pin gauge will move the needle as it is rotated. I see that the original post about Vern's machine was closed for some reason so I hope I'm not ruffling feathers by starting a new one.
Vern Juenke ICC
- Thread starter bluechip
- Start date
Ken Juenke
New member
The ICC will indicate three things:
1. Roundness of the test piece.
2. Jacket thickness variations.
3. Material density differences.
Therefore, you will see variations in a solid pin and a solid copper bullet as it rotates over the sensor simply because they are out of round.
Further, if you warm the test piece in your hands you will also notice the meter indication will change downscale but still show the same unit spread on the meter.
Conversely, a cooled test piece will shift meter movements upscale.
We recommend you use insulated tweezers when handling bullets and allow the entire set of bullets to be tested to come to the same temperature before testing.
Ken Juenke
1. Roundness of the test piece.
2. Jacket thickness variations.
3. Material density differences.
Therefore, you will see variations in a solid pin and a solid copper bullet as it rotates over the sensor simply because they are out of round.
Further, if you warm the test piece in your hands you will also notice the meter indication will change downscale but still show the same unit spread on the meter.
Conversely, a cooled test piece will shift meter movements upscale.
We recommend you use insulated tweezers when handling bullets and allow the entire set of bullets to be tested to come to the same temperature before testing.
Ken Juenke
I deducted that a needle movement to the right (towards 50) means the copper is thinner in that area. I confirmed it by scribing the suspected thin area, disc sanding the bullet from the point to the measuring area, carefully polishing for mirror finish, deburring, then measuring the thickness of the jacket with a Mitutoyo toolmakers microscope that reads directly to fifty millionths. The results were the copper was .0003" thinner in the suspected area. Seeing as though the machine has no actual increments, in my case .0003" showed a meter reading of twenty units. So every tenth will read around seven increments. I have sorted almost a hundred that read 1-2 units, but it took seven hundred to get them. I don't want to plug a bullet maker or bad mouth another, but let's say when you start checking your benchrest quality bullets for concentricity, there will be some surprising results.
I believe we are talking about the balance of the spinning bullet. Seeing as though the bullet is rotating at around 200,000 rpm's, it would seem that an out of balance bullet due to the lead being off center would have a very bad effect on accuracy. I hope to carefully test the accuracy results of sorted bullets at the range soon by comparing say, ten of the most out of balance against ten of the best. Seeing as though Vern's machines have been around for years now, obviously there are those that have tried it, either with mixed results or maybe they are good at keeping a secret!
Ken Juenke
New member
Great Work !
Bluechip, I'm impressed. Thank you for the work you did to come to your conclusion. It is interesting to note my dad found .0003" equated to 15 deviation units indicated on the meter. This is very close to your finding of 20 units.
Ken
Bluechip, I'm impressed. Thank you for the work you did to come to your conclusion. It is interesting to note my dad found .0003" equated to 15 deviation units indicated on the meter. This is very close to your finding of 20 units.
Ken
mario f
New member
I.c.c.
I use since years I.C.C. perfect for my bullet making, my bullet is < 5 units .. great tool ... many thanks to Vern and happy to resume production .. Thanks so many
I use since years I.C.C. perfect for my bullet making, my bullet is < 5 units .. great tool ... many thanks to Vern and happy to resume production .. Thanks so many
Attachments
Ken Juenke
New member
Thank you for the information, Mario. Good to hear about your bullet making success!
Ken
Ken
mario f
New member
I.c.c.
thanks to you, I use I.C.C. also for 6PPC cases and especially for quality control while making bullets ... is a truly precious tool made in 2003
thanks to you, I use I.C.C. also for 6PPC cases and especially for quality control while making bullets ... is a truly precious tool made in 2003
jackie schmidt
New member
You are correct, many of us have done this in the past.
Back in the Early 2000's, a fellow shooter let me borrow his Vern Juenke machine, and we tested quite a few bullets using various Rifles, my Rail Gun in particular.
Back then, Fowler's were very popular, as well as Paglias, Cheeks, Watsons, early Eubers, etc. we sorted bullets by the readings of the machine, and shot groups.
There did not seem to be any correlation between the number of lines of deviation and how small the groups were. We wrote this up on Benchrest.com, it's in the archives somewhere. There was a lengthy discussion.
Keep in mind, none of the short range bullets back then would show more than 3 to 4 lines of deviation, very few showed "zero".
Many Long Range Shooters chimed in, and said that they did see a benefit in sorting bullets with the VJ Machine. This leads me to believe that just like many things in Benchrest, how things are affected at 100-200 yards is quite different than out past 600, just like velocity spread seems to be a non factor at 100/200 as opposed to 600/1000.
Since I am getting more involved with Long Range Benchrest, I want to get a VJ Machine. I personally think that is where it's big worth is.
HuskerP7M8
Member
For those of you who have tested in the past or may plan to test in the future, you need to isolate the bullet imbalance caused by the Cg (Center of Gravity) offset.
To do that, it's mandatory that the Cg offset be indexed in the chamber so that the imbalanced bullets are fired with the index positions 180 deg's apart. I guess you don't necessarily have to have the indexes at 180 deg's, but that's the easiest method and the best way to measure the dispersion if you don't have the tools I employ in my testing.
If you don't index the round in the chamber, the increased dispersion becomes random in regards to its location and it will be difficult if not impossible to fire enough shots to prove or disprove the validity of any measuring device that purports to measure the imbalance.
Come to think of it, the concentricity of jackets and the skill of custom bullet makers has evolved so much over recent years that you may still have some difficulty in proving the concept, but it's your best shot (pun intended).
That aside, there is no doubt whatsoever imbalanced bullets are a major source of dispersion as per Harold Vaughn's "Rifle Accuracy Facts" and I've duplicated Vaughn's testing of this subject many times in the past.
For those of you who are lucky enough to have a copy of "Rifle Accuracy Facts", Vaughn even gives you the formulas needed to know exactly where the bullet impacts based on where it's indexed and the amount of offset.
To illustrate the concept and methodology, let me present the following. Granted, it's with rimfire and not centerfire, but it's still simple physics and every single one of you with any curiosity can duplicate it in centerfire.
Rail-Gun with Stiller 2500X/Muller 4MI barreled action. Shot in my ballistic tunnel on 3/2/16, but I've performed similar testing several times over the years.
20 bullets with 0.65 grains removed by drilling a hole to cause a Cg offset.
After mounting the barreled action, I aimed at bull #23 and fired 5 shots using "NO" shots with a Cg offset induced by drilling holes (Group 1 on the target below).
The scope was adjusted to move the POI to bull #23 and 5 more shots were fired again with "NO" Cg offset (Group 2).
POA was moved to the center dot on bull #13 and the following methodology was used:
5 shots with the Cg offset indexed in the chamber @ 12:00 were fired and the POI was at 3:00 (Group 3).
5 shots @ 9:00 = 12:00 Impact (Group 4).
5 shots @ 3:00 = 6:00 Impact (Group 5).
5 shots @ 6:00 = 9:00 Impact (Group 6).
A closer look with some notes I made:
An Excel scattershot chart generated from the x,y point coordinates provided by my electronic targeting software. The chart on top shows every point of impact and the chart on bottom is the calculated and exact mathematical center for each group:
I don't know if my comments will generate any interest or questions, but be aware I have a very busy schedule and it's quite possible I won't find the time to address anything I've said.
Landy
PS I thought it might be helpful to add the following from "Rifle Accuracy Facts".
I've done a little editing to hopefully make it a little clearer, but it's pretty much verbatim for what Harold Vaughn says in his book for those of you who don't have a copy:
“An offset Cg (Center of Gravity) is forced to rotate about the geometric axis while in the bore of a barrel and this is an unnatural condition.
A spinning projectile will always spin about its principal axis and the principal axis always passes through the projectile Cg, if it’s free to do so.
Due to the Cg offset, a tangential velocity component is produced while the bullet is in the bore.
Consequently, the bullet will start spinning about its principal axis and its Cg the instant it exits the muzzle.
This tangential velocity component creates a lateral drift velocity when the bullet exits the bore.
The direction of this lateral drift velocity will be perpendicular to the plane containing both the geometric and principal axes at the instant of muzzle exit.
With the Cg offset located below the geometric axis in the chamber, the bullet will be deflected 90 deg's to the left and impact at the outer edge of a circle defined by the calculated radius of dispersion.”
Radius of Dispersion = 24 * Pi * (MV / Twist Rate in Inches) * TOF * Cg Offset in Inches.
PSS for Ken Juenke. Your father and I used to visit quite often more years ago than I care to remember. I was involved in IHMSA back then and Vern built several pistols for me. It's been too long ago to remember for sure, but Vern may have sent me one of the prototype ICC units all those years ago because he knew I had almost an obsessive desire to test everything under the sun and I had several BR rifles built by Seeley Masker, Fred Sinclair, and several other respected builders in that era. I have a lot of fond memories of visiting with him.
To do that, it's mandatory that the Cg offset be indexed in the chamber so that the imbalanced bullets are fired with the index positions 180 deg's apart. I guess you don't necessarily have to have the indexes at 180 deg's, but that's the easiest method and the best way to measure the dispersion if you don't have the tools I employ in my testing.
If you don't index the round in the chamber, the increased dispersion becomes random in regards to its location and it will be difficult if not impossible to fire enough shots to prove or disprove the validity of any measuring device that purports to measure the imbalance.
Come to think of it, the concentricity of jackets and the skill of custom bullet makers has evolved so much over recent years that you may still have some difficulty in proving the concept, but it's your best shot (pun intended).
That aside, there is no doubt whatsoever imbalanced bullets are a major source of dispersion as per Harold Vaughn's "Rifle Accuracy Facts" and I've duplicated Vaughn's testing of this subject many times in the past.
For those of you who are lucky enough to have a copy of "Rifle Accuracy Facts", Vaughn even gives you the formulas needed to know exactly where the bullet impacts based on where it's indexed and the amount of offset.
To illustrate the concept and methodology, let me present the following. Granted, it's with rimfire and not centerfire, but it's still simple physics and every single one of you with any curiosity can duplicate it in centerfire.
Rail-Gun with Stiller 2500X/Muller 4MI barreled action. Shot in my ballistic tunnel on 3/2/16, but I've performed similar testing several times over the years.
20 bullets with 0.65 grains removed by drilling a hole to cause a Cg offset.
After mounting the barreled action, I aimed at bull #23 and fired 5 shots using "NO" shots with a Cg offset induced by drilling holes (Group 1 on the target below).
The scope was adjusted to move the POI to bull #23 and 5 more shots were fired again with "NO" Cg offset (Group 2).
POA was moved to the center dot on bull #13 and the following methodology was used:
5 shots with the Cg offset indexed in the chamber @ 12:00 were fired and the POI was at 3:00 (Group 3).
5 shots @ 9:00 = 12:00 Impact (Group 4).
5 shots @ 3:00 = 6:00 Impact (Group 5).
5 shots @ 6:00 = 9:00 Impact (Group 6).
A closer look with some notes I made:
An Excel scattershot chart generated from the x,y point coordinates provided by my electronic targeting software. The chart on top shows every point of impact and the chart on bottom is the calculated and exact mathematical center for each group:
I don't know if my comments will generate any interest or questions, but be aware I have a very busy schedule and it's quite possible I won't find the time to address anything I've said.
Landy
PS I thought it might be helpful to add the following from "Rifle Accuracy Facts".
I've done a little editing to hopefully make it a little clearer, but it's pretty much verbatim for what Harold Vaughn says in his book for those of you who don't have a copy:
“An offset Cg (Center of Gravity) is forced to rotate about the geometric axis while in the bore of a barrel and this is an unnatural condition.
A spinning projectile will always spin about its principal axis and the principal axis always passes through the projectile Cg, if it’s free to do so.
Due to the Cg offset, a tangential velocity component is produced while the bullet is in the bore.
Consequently, the bullet will start spinning about its principal axis and its Cg the instant it exits the muzzle.
This tangential velocity component creates a lateral drift velocity when the bullet exits the bore.
The direction of this lateral drift velocity will be perpendicular to the plane containing both the geometric and principal axes at the instant of muzzle exit.
With the Cg offset located below the geometric axis in the chamber, the bullet will be deflected 90 deg's to the left and impact at the outer edge of a circle defined by the calculated radius of dispersion.”
Radius of Dispersion = 24 * Pi * (MV / Twist Rate in Inches) * TOF * Cg Offset in Inches.
PSS for Ken Juenke. Your father and I used to visit quite often more years ago than I care to remember. I was involved in IHMSA back then and Vern built several pistols for me. It's been too long ago to remember for sure, but Vern may have sent me one of the prototype ICC units all those years ago because he knew I had almost an obsessive desire to test everything under the sun and I had several BR rifles built by Seeley Masker, Fred Sinclair, and several other respected builders in that era. I have a lot of fond memories of visiting with him.
Last edited:
Ken Juenke
New member
HuskerP7M8, Thank you for a very detailed and interesting post. Good work.
Thank you for the kind words about visiting with my dad.
He built me a few pistols when I was active in IHMSA and I shot several 40's with them.
We enjoyed the virtual finger poking in the ribs of those shooting their bolt action pistols while we won matches with our T/C Contenders!
Great memories for sure.
Ken
Thank you for the kind words about visiting with my dad.
He built me a few pistols when I was active in IHMSA and I shot several 40's with them.
We enjoyed the virtual finger poking in the ribs of those shooting their bolt action pistols while we won matches with our T/C Contenders!
Great memories for sure.
Ken
For those of you who have tested in the past or may plan to test in the future, you need to isolate the bullet imbalance caused by the Cg (Center of Gravity) offset.
To do that, it's mandatory that the Cg offset be indexed in the chamber so that the imbalanced bullets are fired with the index positions 180 deg's apart. I guess you don't necessarily have to have the indexes at 180 deg's, but that's the easiest method and the best way to measure the dispersion if you don't have the tools I employ in my testing.
If you don't index the round in the chamber, the increased dispersion becomes random in regards to its location and it will be difficult if not impossible to fire enough shots to prove or disprove the validity of any measuring device that purports to measure the imbalance.
Come to think of it, the concentricity of jackets and the skill of custom bullet makers has evolved so much over recent years that you may still have some difficulty in proving the concept, but it's your best shot (pun intended).
That aside, there is no doubt whatsoever imbalanced bullets are a major source of dispersion as per Harold Vaughn's "Rifle Accuracy Facts" and I've duplicated Vaughn's testing of this subject many times in the past.
For those of you who are lucky enough to have a copy of "Rifle Accuracy Facts", Vaughn even gives you the formulas needed to know exactly where the bullet impacts based on where it's indexed and the amount of offset.
To illustrate the concept and methodology, let me present the following. Granted, it's with rimfire and not centerfire, but it's still simple physics and every single one of you with any curiosity can duplicate it in centerfire.
Rail-Gun with Stiller 2500X/Muller 4MI barreled action. Shot in my ballistic tunnel on 3/2/16, but I've performed similar testing several times over the years.
20 bullets with 0.65 grains removed by drilling a hole to cause a Cg offset.
After mounting the barreled action, I aimed at bull #23 and fired 5 shots using "NO" shots with a Cg offset induced by drilling holes (Group 1 on the target below).
The scope was adjusted to move the POI to bull #23 and 5 more shots were fired again with "NO" Cg offset (Group 2).
POA was moved to the center dot on bull #13 and the following methodology was used:
5 shots with the Cg offset indexed in the chamber @ 12:00 were fired and the POI was at 3:00 (Group 3).
5 shots @ 9:00 = 12:00 Impact (Group 4).
5 shots @ 3:00 = 6:00 Impact (Group 5).
5 shots @ 6:00 = 9:00 Impact (Group 6).
A closer look with some notes I made:
An Excel scattershot chart generated from the x,y point coordinates provided by my electronic targeting software. The chart on top shows every point of impact and the chart on bottom is the calculated and exact mathematical center for each group:
I don't know if my comments will generate any interest or questions, but be aware I have a very busy schedule and it's quite possible I won't find the time to address anything I've said.
Landy
PS I thought it might be helpful to add the following from "Rifle Accuracy Facts".
I've done a little editing to hopefully make it a little clearer, but it's pretty much verbatim for what Harold Vaughn says in his book for those of you who don't have a copy:
“An offset Cg (Center of Gravity) is forced to rotate about the geometric axis while in the bore of a barrel and this is an unnatural condition.
A spinning projectile will always spin about its principal axis and the principal axis always passes through the projectile Cg, if it’s free to do so.
Due to the Cg offset, a tangential velocity component is produced while the bullet is in the bore.
Consequently, the bullet will start spinning about its principal axis and its Cg the instant it exits the muzzle.
This tangential velocity component creates a lateral drift velocity when the bullet exits the bore.
The direction of this lateral drift velocity will be perpendicular to the plane containing both the geometric and principal axes at the instant of muzzle exit.
With the Cg offset located below the geometric axis in the chamber, the bullet will be deflected 90 deg's to the left and impact at the outer edge of a circle defined by the calculated radius of dispersion.”
Radius of Dispersion = 24 * Pi * (MV / Twist Rate in Inches) * TOF * Cg Offset in Inches.
PSS for Ken Juenke. Your father and I used to visit quite often more years ago than I care to remember. I was involved in IHMSA back then and Vern built several pistols for me. It's been too long ago to remember for sure, but Vern may have sent me one of the prototype ICC units all those years ago because he knew I had almost an obsessive desire to test everything under the sun and I had several BR rifles built by Seeley Masker, Fred Sinclair, and several other respected builders in that era. I have a lot of fond memories of visiting with him.
Dude this is beayooootifull!
Good On Ya
BTW, drilling lead is fun ain'it?
From Iceland
New member
HuskertPM8
Dear Sir! (HuskerPM8)
Excellent post
Thank you!
Magnus Sigurdsson
Reykjavik
ICELAND
Dear Sir! (HuskerPM8)
Excellent post
Thank you!
Magnus Sigurdsson
Reykjavik
ICELAND
Lee Martin
Active member
Ken - thanks for bringing the machine back. Are you taking pre-orders? I'm sure I'm not the only one wanting to get in line for one.
-Lee
www.singleactions.com
-Lee
www.singleactions.com
Ken Juenke
New member
Hi Lee,
I don't want to violate the rules of this forum by doing business here so please feel free to email me at support@iqwurks.com or PM me here.
Ken
Lawrence W.
New member
Hello Ken.
A great place to advertise your new Bullet Comparator, is right here on the Benchrest Central classifieds. Dirt cheap and everyone gets to see it.
A great place to advertise your new Bullet Comparator, is right here on the Benchrest Central classifieds. Dirt cheap and everyone gets to see it.
Ken Juenke
New member
Hi Lawrence, I went to the classifieds page but cannot find any contact info there. Are you managing that space for benchrest.com?
Lawrence W.
New member
Hello Ken.
No, I do not manage anything to do with Benchrest.com.
Over the years I have bought and sold a bunch of stuff on these classifieds. They are a very effective way to reach out to the Benchrest crowd. You can get started by going to:
http://benchrest.com/class/
You will have to set up a new User Name to list anything.
I have also owned and used one of your dad's original Juenkes for the past 15 years and am a true believer.
Good luck.
No, I do not manage anything to do with Benchrest.com.
Over the years I have bought and sold a bunch of stuff on these classifieds. They are a very effective way to reach out to the Benchrest crowd. You can get started by going to:
http://benchrest.com/class/
You will have to set up a new User Name to list anything.
I have also owned and used one of your dad's original Juenkes for the past 15 years and am a true believer.
Good luck.
Ken Juenke
New member
Lawrence, thank you very much for the info. I'm really happy to read about your joy with my dad's ICC. I'm very excited to finally get to participate in keeping the concept alive and working!