Internal Concentricity Comparator (I.C.C.) Unit?

[Donna]

Hello ya all,

Has anyone tried the “Internal Concentricity Comparator (I.C.C.) Unit” from the Accuracy Den by Vern S. Juenke? And if so what is your take on it?

The I.C.C. unit uses an ultrasonic detector to indicate the amount of metal mass and has a motor that slowly turns the bullet over the detector. The amount of metal mass is indicated on an analog meter movement that is marked of from one to fifty in units of one, these are dimensionless numbers.

I have seen several pitfalls to this instrument. Several of these pitfalls are mentioned in their literature. You can get different readings depending on where along the length of the bullet the readings are taken from. The instrument needs about one half to one hour to warm up before the meter movement no longer drifts. The difference between the room temperature and bullet temperature will adversely affect the readings as will the amount of tarnish that is on the bullet. To me, the I.C.C. unit is liken to a bubble balancing machine for your car’s tires, type that the wheel must be taken off the car and placed on the machine vice the type that balances the tire while it remains on the car and the tire is spun up for balancing. While the first one will get you by, the second on will give you much better results. I have tested about 300 of my own bullets on the I.C.C. unit but I have yet to tell the difference between the bullets at the target (100 yards). The bullets tested cover the full range from 0 to 50, being separated in groups of 5’s (0-5, 6-10, 11-15, …, and so on). But on thing was dramatically evident by the I.C.C. unit and that was the difference in readings of a bullet before and after it was dropped from a height of only 3 to 4 ft. and then test fired. I took one of my bullets that read in the range of 0-5, dropped it from a height of about 4 feet then read it again. This time it read in the 20-30 range and instead of firing less than 1/2 MOA it was greater than 3 MOA (firing was done at 100 yards). But it is strange that my new bullets that have the same amount of difference in readings do not seem to be adversely affected at the target as the dropped bullet was. Scratching my head!

Donna :wink:

[talon]

first response: HuH?
  Then... could it be that the ICC's needle movement isn't a proper measure: what you need is something that indexes the bullet and then measures the variance along the X( length) as well as the Y(degrees around the circumference) axis. That needle swinging back and forth could be measuring random mass differences in a 'normal' bullet that more or less balance out. When you drop a bullet on the floor, the puppy flattens out ever so slightly along some length of the x axis, but only at one point on the y (the side that hit the floor). This throws it out of balance when fired several orders of magnitude more than one with multiple  random variance. You would observe the reasons clearly on a static X-Y chart. My thoughts. I've never visited an ICC machine.

[Clint Starke]

The best way to spin a bullet is down the barrel, and let the target be the indicator of accuracy. I've had bullets test 0 on a Junke, and between 20 and 25. All shot the same.

If one shoots only factory bullets in competion, not hand swaged, then it might pay. It would help find those few bad bullets. Spining hand swaged bullets made from good jackets is splitting hairs that don't exsist.

C.S.

[Donna]

Thanks Talon and Clint for your input.

Clint – I agree with you on this I.C.C. unit. :wink:

Donna