An interesting machine. Care must be given to calibration, before and
especially during testing. There are two tests for flat base bullets and
three for boattail designs. Essentially, you check ogive and boattail
runout as well as body out-of-round and voids between jacket and core.

The 8mm Hornady's looked fabulous in the body, less so in the ogive. The J36
are definitely "golden beebee's" - only one of the ten I tested was more
than 5 DU. Many were less than 3. Some Partitions looked stellar, others,
not so fine. I didn't get to the X bullet yet.

One item of particular note: Bullets are FRAGILE. The manual says a bullet
dropped on the floor is likely to be worthless. I had to test this. I found
an A-max 140gr in 6.5mm that read 6 DU (deviation units) or less in all
tests. This is one notch below golden BB status. I dropped it from waist
level on the concrete floor of my shop. Destroyed! The body would not read
less than 28 DU and the ogive was completely off scale. What a wake-up call.

Deviation Units

0-5 Golden BB's, Bench rest gems.
6-10 Very good.
11-15 Fair bullets, fine for hunting.
16-20 Group openers, not quite flyer class, but no good for competition
21 and above, True flyers. Will always stray from POI. (toss them)

I now need to come up with a sorting tray and then develop a test routine
for each caliber.

More Juenke work.

The key to the Juenke is to devise a test for each bullet that ferrets out
the bullet's weakness. Initial work suggests the tests will be different for
each bullet in each caliber - meaning you'll have to write them down as to
set up.

For instance, first tests with the 8mm 220gr Hornady suggested that every
bullet was a golden BB. When placing the body across the carbide balls,
every one or almost every one was reading in the 2-4 DU range. Now, we know
this can't be a true representation or Hornady would have put Berger and the
likes out of business a long time ago. It does indicate that Hornady's
process for slugging the core into the interlock body is pretty darn good.

I then repositioned the bullet on the balls with the right set of balls well
down the ogive as suggested in the manual. This did not work. The base kept
trying to climb the plastic stop as the bullet rotated. Even a tiny movement
sends the needle careening off scale. So I turned the bullet around,
opposite to the manual, with the nose against the stop and the right ball
pair just in front of the cannelure. This worked fine and showed me where
Hornady's Achilles' heel is. The manual mentions the possibility of uneven
folds in the ogive part of the jacket and here is where these bullets
deviated. The fold is internal, invisible, and established in the bullet's
final forming process. The ultrasonic wave of the Juenke can detect it.

I tested 112 bullets and separated them into categories as below:

0-5DU = 19 bullets
6-10DU = 38 bullets
11-15DU = 30 bullets
16-20DU = 18 bullets
20+DU = 7 bullets

This shows the Hornady's are trying to be good, in fact very good. 75% are
good hunting bullets. 50% are good bench rest bullets. There were trends. In
the 6-10 group, most were either 6-7 or 9.5-10. Same in the 11-15 group.
Most were right at 11-12. It's tempting to think of these categories like
case weight and resort the categories to match the trend. This would be
wrong. Anything over 10 is going to fly worse than the 6-10. 11's will open
up more than 10's, so why reduce the precision for the sake of including
more bullets in one particular group.

I like these results. It tells me more than half of my 8mm bullets are
really good. And the seven 20+ can be relegated to foulers and appropriately
marked.

Developing the test and doing all the bullets took about an hour. Developing
the test took at least half that time. The 8mm test would not work for .264
Amax as the nose of the bullet slips under the plastic stop. But positioning
the bullet on the balls as per the manual worked just fine.

More later.

Rod,
I would be interested in seeing range reports of the variation in group size from the different categories. A head to head- same load - same seating depth shootout. Very interesting results your getting from the same(?) lot of bullets.
Good Shooting,
Tiger

P.S. Waiting on the short action is killing me

Rod - I'm curious, what do you (or should I say "how" do you)calibrate? I'm getting the feeling this test does a good job comparing bullets against each other, but not against a standard. And you mentioned calibration during the process - that's a major "no-no" in my field. (mechanical operations and engineering)

Don't get me wrong, I'm not trying to shoot down your testing, just trying to get a clear picture of the procedure.

Another question, have you noticed any difference deviations between lot #'s? In other words the J36's out of your test went 3-5 DU - have you compared those results with another batch of J36's?

The range work comes next. First step was to "understand" the machine and use its capability to segregate bullets. The big question is: do I have a rifle capable of showing distinct results. If the rifle is not capable of quarter minute angle, I may not be able to prove anything. Let's hope the 6.5-284 Norma can make the grade as a trial horse.

One of the "issues" is slight variations in mass, usually not diameter, but length. The manual states how slightly longer or shorter bullets will read "off scale". You need to rezero to get a DU range on runout, which is what we are trying to detect.

Hence, recalibration on the fly is to get the meter back in the central zone when a longer or shorter bullet is detected. You could further segregate this way too, and most benchrest people who use this machine do. (high/small DU and low/small DU).

Calibration is done by a series of knobs on the front of the machine. I suspect they are rheostats that allow levels from the detector to be balanced to the meter's range. The goal is to find a "test" bullet and then use it as the standard for all the remaining bullets in the inventory. One can only reach this goal by testing a LOT (many) of bullets. Is the high or low range the standard? What about lot to lot? 112 bullets is not enough to select my "standard" bullet for the 8mm 220gr Hornady. I have about 500 of them. I'll test them all for runout, then go back and separate the 0-5 and the 6-10 into high scale and low scale bullets. Hopefully there will be an abundance of one over the other. If not, them maybe TWO standard bullets. Paint them red or something.

The J36 comes 20 in a box, standing on the base in a foam filler drilled with 20 little holes - like missiles in silos. They do not touch each other. You could throw the box across the room and the bullets would likely not touch anything but foam. Contrast this to how other bullets are packed. Maybe there is correlation. I once had three boxes but have fired the bulk of them and am probably down to less than 20. I did not retain the original packaging, but rather dumped them into a plastic tray in my bullet storage bin - all three boxes together. So far, I've only looked at about 10.

What I was really interested is how Barnes X would fare. There is no jacket issue but the X bullet (for me) has never shot the way I hoped it would - in any rifle. I've always suspected the cavity in the nose might be a little off center in many bullets. The Juenke machine should tell the story here. I have oodles of 7mm 120gr X to look at. I also have X bullets in .264, 8mm, .375, .416, .458 and a pesky .30cal that managed to creep into my gun cabinet when I wasn't looking.

Wanted to look at Partitions too, and compare them to Ballistic Tips. And especially look at Partitions damaged in the magazine by recoil (flattened noses). And of course, I'll have to shoot a lot to prove the numbers mean anything.

Rod

[ 06-07-2003, 11:14: Message edited by: Rod@Acrabond ]

I too am very interested in the test firing portion of your test. I know of two very good Highpower Rifle Competitors who owned Juenke Machines then sold them. One of them has the intials of GDT if that means anything to you. The other commented that he could not correlate the accuracy he observed at long range (600 to 1000yds) to the Deviation Units shown on the Juenke.

I'd have to add that Highpower Rifle accuracy standards are not at Benchrest Standards however.

BTW, aren't the J36's homogenous Copper/Nickel Alloy, and thus free from any core problems?

[ 06-07-2003, 11:54: Message edited by: Chris F ]

Very interesting Rod, looking forward to reading as you post more too. This is the best account I've heard from someone using one of these as far as how they function and what the results are etc, very good info! Appreciate the time and effort in sharing this with us!! I posted a link to this at longrangehunting.com too.

The J36 are solid, homogeneous, but they are not free of runout, both on the body and in the ogive. There is deviation (runout) but it is small on all but one bullet. I have only a very small sample (less than 20) so the numbers may not correlate over a larger lot.

On 8mm 220gr Hornady, they did. I tested 320 today, got about the same results the smaller lot predicted.

65 units at 0-5
136 units at 6-10
75 units at 11-15
29 units at 16-20
15 units at 20+

Also selected four 'standard' bullets that measured 2-3 DU in the middle of the common range. In the future, I'll calibrate the machine to these four before testing bullets.

Next step is a "blind" test. A friend will pick ten rounds from each my bins and place the bullets in baggies marked with words randomly chosen from the dictionary. He'll record where they came from but withhold that information. I'll then load ten rounds of each and shoot groups at 200 yards. We shall see.

Rod,
I like what you're doing...Blinded and encoded by your friend. Please keep us posted.

Rod,

I have a Juenke meter in hand for testing and have no instruction manual for it. Can you help?

You have mail.

Thanks for any assistance you might provide.

I got a hold of Vern today, his wife faxed me a copy of the manual.

Very interesting reading guys. I look forward to more of your results.
Jeff

I'll add to Rods topic here what I found so far just getting started with the I.C.C. and sent him in an email.

More later, but so far the 200gr Accubonds all tested under 9 DU's on the shank, half were under 4 DU's, the other half were 8 DU.... not bad I thought. The 178 A-Max's I checked were in the same range too. All 10 .338 300gr SMK's I checked were all less than 3 DU's.

I've made a couple observations so far; A couple things can cause higher DU readings than it really is because of the tip or base length variations can cause the bullet to move left or right on the balls varying the distance to the detector head if it is not level, as with testing boattails or ogives. If it was not distance sensitive, this would not matter but, it is and is something to consider.

I thought of making an vertically adjustable stop that fastened to the originals lock-down screw that would center on the bullet bases axis to elliminate it from riding the stop on the heal of the boattail, this would keep the heal irregularities from influencing the distance to the detector, as it should remain stable from lft to right.

With the bullet tip to the left against the stop and setting at quite an angle to test ogives, I can see no way to correct for variations in irregular tip length like you get with the SMK bullets.

So many ways to sort them all, a guy might end up with many, many DU batches in just one box of a hundred. More time and blind tests will tell what works best.

It's a well designed unit that should distinguish best, good and bad bullets for sure. Ogives seem to throw out higher DU's than shanks, but it could be the tip ot heal that is causing some of it too, so who knows yet.

I would be very interested how well you could read two things, the squareness of the flat or boattail base to the axis, besides center of mass imperfections.
I talked to Vern on the phone. He put a big emphasis on squareness of the base problems in a lot of supposedly well swaged bullets. - Lew

I don't see a way to with the Juenke ICC, but if I'm missing something let me know. It will affect the DU reading if it's not square to the axis and the bullet's spinning on the ogive or BT, as it will let it ride up or down on the bearings and change the distance from the sensor. You have know way of knowing which was is causing the DU ranges exstreme reading tho, the base squareness or irregularities in the ogive or boattail.... something isn't right with it though... that's a fact.