168 JLK BC ?

[Elwood]

Does anyone know the true BC of the 7mm 168 grain JLK?
I believe the 180 JLK has been given a .710 BC but the actual BC is .660?

The 168 JLK is quoted as .690 which I would think is some what inflated? My reason for enquiring is that lets say that the BC drops to roughly .650 then if a 284 Shehane can push this at 3100 fps with the right powder then it should be on par with the 7 WSM's using the Berger 180 Vld, but with more barrel life.

Having looked on the JLK and Berger websites I have found that JLK state a 1-9.5 twist and Berger say a 1-10 twist for the 168 grain bullets. Having emailed all the major barrel manufactures what they would recommend (Thank you Bartlein, Brux and Krieger for replying) I was given a 1-9 twist answer.

I have no doubt that there's something that I have over looked but it would seem to be a sensible base for a highly competitive F open combination dependant on BC and velocity?

 

[Elwood]

So no one has experimented with 168 JLK or Bergers in either a 1-9 or 1-10 twist 7mm ?

 

[JamesBailey]

OK, I will chime in here, although I don't have direct experience w/ the 168JLK.

So the 7mm JLK dies are nearly the exact same as the Berger 7mm dies. If you look at the 180gr JLK v the 180gr Berger VLD you will note that they are nearly the exact same dimensions. Not surprisingly, they shoot nearly the exact same ballistic path. The G1 BC that Swampy is carrying on his website for the 180gr JLK (.70+) is way high, or at least I am very skeptical of it.

Ergo, I assume that the 168gr JLK is a near copy of the 168gr Berger VLD. I don't think you will grab a bunch of BC with the JLK over the Berger. Sorry. I could be totally wrong however.

You will have no problem with a 1:9 twist stabilizing any 168gr 7mm bullet, unless you are moving them at a super low speed (<2600).

I will tell you that one bullet caliber that the JLK do outshoot the Berger's in is the 6.5mm - both the 140 and 130gr JLKs are awesome bullets and your idea of grabbing BC AND MV works very well with the 130gr JLK.

 

[Shooter264]

I don't really have any experience with the 168 JLK's but I shoot the 180's in my 7mm. I have about 300 of them but I tried the 180s first and they shot great. Out through 1125 yards I have come up with a BC of .690. That's a bit short of the .730 that they claim but they shoot lights out. The Berger 180's run about .650 in my testings and do not shoot as good in my 7mm.
I have a 6.5x47L that shoots the 130 JLK's at a .590 BC and they are advertised as a .620ish. I am guessing your 168's should run somewhere in the range of .650 or there abouts.

 

[Keith Glasscock]

Unfortunately, G1 BC's really aren't very useful for long-range shooting. If it were me, I'd use the G7 BC developed by Bryan Litz for the Berger 168 realizing that the two bullets are very close in profile.

Do keep an eye on your meplat diameters. An increase of .015" in diameter there can negatively impact BC by 2%

 

[Elwood]

James, Busdriver and CPGFan, many thanks for the comments, I have found them most useful.

 

[flatlander]

I bought a bunch of 168 & 180 VLDs from JLK a few years ago, and immediately set to comparing them to the Bergers of the same weight in my 284s. Like the other guys have mentioned, the two brands are extremely close in shape, at least these two 7mm bullets. The only way I could tell the JLK 168s from Bergers is the JLKs have a dimpled base. Sure enough, when shot with the same loads, POIs were nearly identical out to 1000yds. Bryan Litz's G1 BC for the Berger 168 is .617, while the G7 value is .316.

My 284 bbls. are: (2) 30" hvy Palmas, one Bartlein & one Krieger (1) 28" custom contour PacNor 3-groove - all are 1:9tw.

 

[Elwood]

Flatlander, funny you should mention the dimples as a friend of mine has some JLK's with dimples, but mine haven't.
He was told the British army used this design with field gun projectiles and were able to get extended ranges that no one else could given the same weight shell and equivalent powder.

So it would seem that as of yet there aren't any bullets in the 160-168 grain weight that have a BC of over .620 give or take a few points, shame really as I think they would be ideal for the .284 or Shehane.

Thanks for all the info.