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Anyone using JLK 7mm bullets

Greene

Team Copper Creek
Commercial Supporter
Full Member
Minuteman
Aug 7, 2010
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Albany, Kentucky
Was browsing the web and ran across JLK and they claim the 7mm 168gr has a BC of .690 and the 180gr BC is .735 and are supposed to be thin jack and can be hunted with. Anyone tried these? What's your opinions?

I'm currently using 168-180 Berger vld hunting as my do all round for target and long range hunting/coyote round.
 
Re: Anyone using JLK 7mm bullets

I have 500 of the 180 JLKs (well, 460ish).

First the bullet is almost identical to the 180 berger. Actual BC is alos identical to the 180 berger. The advertised BC of the JLK bullet is apparently inflated. I haven't shot enough of them to test for myself. I found a few places on the net confirming this.

So far I haven't shot them enough to verify accuracy of the bullet. Still working on ladder and OCW testing. But they are a bit cheaper than the bergers.

copied and pasted from accurate bulletin (bottom) berger vs jlk

DIAGRAMS are available on web page. TEXT to follow

7mm Bullet BC Testing — Evaluating the Numbers
Bryan does a lot of testing for bullet-makers, evaluating the performance of various bullet types. One thing he has observed is that manufacturers’ published BCs may vary considerably even for two bullet designs that appear to be nearly identical. In our Forum, Bryan offered this interesting analysis of the 7mm Berger 180gr VLD and the similar 7mm JLK 180gr VLD:

“I’ve developed a repeatable procedure for test firing bullets to determine ballistic coefficient. If you get Precision Shooting Magazine, the March issue has one of my articles about test firing the Berger .30 cal 155gr VLD. Long story short, my test procedure uses acoustic sensors in 200-yard increments to measure time of flight out to 600 or 1000 yards. My BC measurements are repeatable to within +/- 2%, usually within +/- 1%.

I have tested several 7mm bullets. Of particular interest are the Berger 180gr and JLK 180gr bullets. If you look at these bullets side by side, it’s hard to tell a difference between them. I believe the JLK bullet dies were made from the same set of prints as the Berger VLD (Design by Bill Davis of Tioga Engineering). So … why would these bullets have different [published] BCs? They’re the same weight and the same basic shape [with very minor differences in OAL and bearing surface length]. This is just the kind of smoke and mirrors that makes shooters think there is something mysterious about BCs and exterior ballistics that’s beyond the realm of human understanding. I was pleased with the results of my testing of these two bullets: the BC is virtually the same, as expected. All is right with the world.”





Drag Models — G7 is better than G1 for long-range Bullets
Most ballistics programs use the default G1 drag model. Bryan believes the G7 standard is preferrable for long-range, low-drag bullets: “Part of the reason there is so much ’slop’ in advertised BCs is because they’re referenced to the G1 standard which is very speed sensitive. The G7 standard is more appropriate for long range bullets. Here are the results of my testing for these two bullets:

G1 BCs, averaged between 1500 fps and 3000 fps:
Berger 180 VLD: 0.659 lb/in²
JLK 180: 0.645 lb/in²

The reason the BC for the JLK is less is mostly because the meplat was significantly larger on the particular lot that I tested (0.075″ vs 0.059″; see attached drawings).

For bullets like these, it’s much better to use the G7 standard. The following BCs are referenced to the G7 standard, and are constant for all speeds.

G7 BCs:
Berger 180 VLD: 0.337 lb/in²
JLK 180: 0.330 lb/in²

Many modern ballistics programs, including the free online JBM ballistics program, are able to use BCs referenced to G7 standards. When available, these BCs are more appropriate for long range bullets.”

[Editor's NOTE: BCs are normally reported simply as an 0.XXX number. The lb/in² tag applies to all BCs, but is commonly left off for simplicity.]

Effect of Bullet Pointing
Bryan has also tested the effect of pointing bullets. He’s determined that this does have a positive (if small) effect on ballistics. Bryan writes: “I have measured the Berger 180 VLD in both nominal and pointed meplat configurations. Pointing the meplat from 0.059″ to 0.039″ increases the G7 BC from 0.337 lb/in² to 0.344 lb/in². This results in less than 2″ difference in 1000-yard wind drift (10 mph 90°). The improvement is small, perhaps negligible for standard decimal prone targets with large scoring rings. The improvement is more significant for F-Class targets with smaller scoring rings. That being said, I do point my own Berger 180 VLDs that I shoot in prone competition. It’s fast, easy, doesn’t hurt anything, and every little bit helps.”
 
Re: Anyone using JLK 7mm bullets

That BC seems rediculously inflated if you ask me.

How can these be .735 while the bergers are .66. I would say the accuracy of the BC measurement for the JLK is way off.
 
Re: Anyone using JLK 7mm bullets

I was shooting 180 bergers and thought I would try the 180 JLK's. According to the ballistics programs using it's BC , I would be 0.3 Mils flatter at 1000. But when shooting the JLK's the exact same speed, I used exactly the same dope as for the 180 bergers. I thought I was gaining something by going with the JLK's, but really they are just the same as the 180 bergers. And I'm not real fond of the bigger meplat on the JLK's.
 
Re: Anyone using JLK 7mm bullets

I use both. I use the Whidden Pointing die on all my bullets & have found that the JLK's are easier for me to get to shoot. I always have to make sight adjustments at 1,000 yards from day to day so the same sight setting with both bullets gets me on paper @ 1000 yards. I have more JLK's than I have Berger's for whatever that is worth.
 
Re: Anyone using JLK 7mm bullets

Hence the reason that I have switched to the Berger Hybrid 180s. You do not have to chase the lands like you do with VLD bullets to maintain consistent distance to the lands. The Hybrids are less sensitive to seating depth due to the hybrid ogive. The meplat of the hybrid is also more like the JLK which leads itself nicely to pointing if needed. Also, the BC of the Hybrid 180s is greater than either of the VLD bullets. (The BC of a pointed Hybrid gets real close to 0.7)

I also like the Matrix 190g VLD bullet if shooting VLDs. I doubt the listed BC on the website, but out to 600 yards(the farthest I have shot the Matrix VLDs), the BC seem to be that of the Hybrid or slightly higher. (Same dope as the Hybrid to 600 yards at 100fps less velocity)
http://www.matrixballistics.com/.284-Caliber-rifle-bullets.html