Range Report 130gr JLK by the numbers - evaluate my analysis

[jbailey]

Now that the 6.5 jackets are rolling again, my order of 130gr JLK's is finally in the mail from the Swampworks. Not having very good data on them, I did some math analysis of my own and I wanted to share it with you all for critical comments.

As a reference point, I am a tactical competition shooter and shoot a 6.5x47L 26" with a 140gr Berger LR-BT over 38.2gr of RL-15 that does 2865fps 12' from muzzle with 0.25-0.50moa groups out to 600 with an ES around 10. I am happy with it, but always looking to push my ballistic signature

<span style="font-weight: bold">BC G1 and G7</span>

According to Swampy, the 130gr JLK has the same external dimensions as its big bro, 140gr JLK. Since Bryan Litz has fully characterized the 140gr, we can do some math with his work to understand the 130gr better: most importantly, we know that the 130gr JLK has the same form factor as the 140gr JLK (BC G7 = 0.878, G1 = 0.451, the lowest form factor of ANY bullet Bryan tested). So only difference between the 140gr and 130gr JLKs is the sectional density. Armed with that info, we can calculate the 130gr JLK G1 and G7 BC's from Bryan's 140gr JLK data. <span style="text-decoration: underline">I calculated a 130gr JLK G7 BC of 0.303 and a G1 BC of 0.590 (.266/.878 and .266/.451).</span>

<span style="font-weight: bold">Velocity</span>

I know can safely and accurately get a 140gr going at over 2865fps. If we assume the same chamber pressure, <span style="text-decoration: underline">we can calculate that the 130gr JLK might be able to do 2973fps 12' from muzzle </span>(square root of (V^2*W of 140/W of 130)).

<span style="font-weight: bold">Seating Depth</span>

We also know that the 130gr JLK has an Rt/R ratio of 0.75 (same as the 140gr JLK), which means it should be less sensitive to seating depth than Berger’s two VLDs (both with secant ratios of 0.58) but more sensitive than the 142gr SMK or the 140gr Berger LR-BT (SMK = 0.84, Berger = 0.95). I have a chamber with a 0.1814" freebore and plan to shoot the JLK off the lands.


<span style="font-weight: bold">Conclusion</span>
IN THEORY, we have a very attractive bullet profile. We are shooting a bullet with equal BCs to the 142gr SMK, but at 100-150fps or so faster. It is close to the performance of the 6.5x284, but with better barrel life profile. For tactical shooting, it will offer the less drop and only drift a bit more than the Berger 140gr VLD and 140gr JLK. Field tests will be interesting!


Any comments on any of this are appreciated. Thanks.

 

[BryanLitz]

Re: 130gr JLK by the numbers - evaluate my analysis

^^ That's what I'm talkin' about^^!!

Great analysis James. I agree with your assessment of the BC's for the JLK 130 VLD, as well as the expected velocity based on what you get with the 140.

Go forth and reap the benefits of your knowledge!

BTW, some more recently discovered middle weight 'gems' for the 6.5mm are the Norma 130 grain Diamond and the 131 grain Cauterucio. I don't know about precision with these bullets, but their form factors are both below .910.

Don't think I'm taking this lightly either. Berger can't be outdone on low drag designs on my watch!

 

[blklabs]

Re: 130gr JLK by the numbers - evaluate my analysis

Keep us posted. I have 900 of the 140 JLK bullets in the mail to test with. It will be interesting to see what your results are.

 

[ChadTRG42]

Re: 130gr JLK by the numbers - evaluate my analysis

Very nice. I am also doing the same calculations with my 260 Rem. I've been running pointed 140's in the past but am switching to pointed 130 VLD's. Earlier this week I finalized my load pushing the 130 VLD's to 2984 fps with a 2 fps ES. It shot a 1.1" group at 389 yards. I think I'll take it!
Comparing it to the 140 VLD I'm running at 2840, I'm giving up about 3" to 4" of added wind drift at 1K. I think I can live with that. It shoots a lot flatter than the 140, which I think will work well for hold overs and UKD's. So, I'll also plan to run the 130's from here on out.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChadTRG42</div><div class="ubbcode-body">Very nice. I am also doing the same calculations with my 260 Rem. I've been running pointed 140's in the past but am switching to pointed 130 VLD's. Earlier this week I finalized my load pushing the 130 VLD's to 2984 fps with a 2 fps ES. It shot a 1.1" group at 389 yards. I think I'll take it!
Comparing it to the 140 VLD I'm running at 2840, I'm giving up about 3" to 4" of added wind drift at 1K. I think I can live with that. It shoots a lot flatter than the 140, which I think will work well for hold overs and UKD's. So, I'll also plan to run the 130's from here on out. </div></div>

Chad -
are these JLK's VLDs? Whose ever they are, they are certainly fine projectile in your load/rifle! Nice Work. If they are JLK's do you have any estimated BC numbers, or drops?

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body">^^ That's what I'm talkin' about^^!!

Great analysis James. I agree with your assessment of the BC's for the JLK 130 VLD, as well as the expected velocity based on what you get with the 140.

Go forth and reap the benefits of your knowledge!

BTW, some more recently discovered middle weight 'gems' for the 6.5mm are the Norma 130 grain Diamond and the 131 grain Cauterucio. I don't know about precision with these bullets, but their form factors are both below .910.

Don't think I'm taking this lightly either. Berger can't be outdone on low drag designs on my watch! </div></div>

Bryan-
thanks for the encouragement. I'm simply following in your foot-steps and this math stuff is kinda fun when highly accurate rifle projectiles are involved!

I have a buddy who shoots the 130 Norma and they are absolutely lights out in his 260Rem. He has bench shot some 0.15moa groups with them, so they are clearly very precise.

I personally love the Berger line, with a big thumbs up on the 140gr LR-BT. Would love to see some sub 0.90 form factors however, as everyone can always use a lower form factor

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

UPDATE ON THE JLK 130gr 6.5mm's

A buddy and I have done some load development w/ the JLK 130gr in his 6.5x47L. We are loading it mag length with H4350. He found the low-end accuracy node at 41.7gr doing 2910fps out of his 26" Krieger. Don't know how high up he went, but this charge was the most accurate he tested. I'm not happy with 2910, so I will go higher once I start development.

The update however is the BC. We are using the G7 BC of 0.303 that I calculated and Bryan said sounded about right. My buddy had this load/rifle out at a prone tactical match over the past weekend based on a dope off of the 0.303 G7 BC. He was 33 of 33 first round hits from 100 to 850 yards - and all of the hits were dead center, except the 680 yd target which was a 0.25moa high (could have been the shooter

). He won the match and we are very encouraged by this excellent bullet. 0.303 has got to be very close to the actual BC given these field results. The 130gr JLK is clearly very accurate with an outstanding ballistic profile.

 

[BryanLitz]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">He was 33 of 33 first round hits from 100 to 850 yards</div></div>

Ballistics ROCKS!

oh, and good shooting too

 

[damoncali]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">
<span style="font-weight: bold">Velocity</span>

I know can safely and accurately get a 140gr going at over 2865fps. If we assume the same chamber pressure, <span style="text-decoration: underline">we can calculate that the 130gr JLK might be able to do 2973fps 12' from muzzle </span>(square root of (V^2*W of 140/W of 130)).
</div></div>

I'm not following what you're doing here. Could you explain a little?

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: damoncali</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">
<span style="font-weight: bold">Velocity</span>

I know can safely and accurately get a 140gr going at over 2865fps. If we assume the same chamber pressure, <span style="text-decoration: underline">we can calculate that the 130gr JLK might be able to do 2973fps 12' from muzzle </span>(square root of (V^2*W of 140/W of 130)).
</div></div>

I'm not following what you're doing here. Could you explain a little? </div></div>

Sure. What's going on is a model suggested by Bryan Litz for estimating velocity of a different weight bullet based on known velocity for another bullet of same caliber/cartridge, but different weight.

The model assumes that if the two same caliber bullets are pushed with equal chamber pressure, they will have equal kinetic energy at the muzzle. We know that E (kinetic energy) = 1/2 mass * velocity ^2. So if E of bullet 1 = E of bullet two, we can Algebraically isolate the unknown velocity because we know all the other variables:

1/2 mass of bullet 1 (known) * velocity of bullet 1 ^2 (known) = 1/2 mass of bullet 2 (known) * velocity of bullet 2 ^2 (unknown)
->
velocity of bullet 2 ^2 = mass of bullet 1 * velocity of bullet 1 ^2 / mass of bullet 2
->
velocity of bullet 2 = (mass of bullet 1 * velocity of bullet 1 ^2 / mass of bullet 2)^1/2
->
velocity of bullet 2 = velocity of bullet 1 * (mass of bullet 1 / mass of bullet 2)^1/2

This model is an estimate only and is sensitive to internal ballistic variables not captured in the model, e.g. different surface bearing areas, small different in bullet radii, etc. Nevertheless, I have found it to match real world results pretty well and use it in my bullet analysis as result.

It is just one of the pearls of wisdom from Bryan's "Applied Ballistics".

 

[damoncali]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: damoncali</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">
<span style="font-weight: bold">Velocity</span>

I know can safely and accurately get a 140gr going at over 2865fps. If we assume the same chamber pressure, <span style="text-decoration: underline">we can calculate that the 130gr JLK might be able to do 2973fps 12' from muzzle </span>(square root of (V^2*W of 140/W of 130)).
</div></div>

I'm not following what you're doing here. Could you explain a little? </div></div>

Sure. What's going on is a model suggested by Bryan Litz for estimating velocity of a different weight bullet based on known velocity for another bullet of same caliber/cartridge, but different weight.

The model assumes that if the two same caliber bullets are pushed with equal chamber pressure, they will have equal kinetic energy at the muzzle. We know that E (kinetic energy) = 1/2 mass * velocity ^2. So if E of bullet 1 = E of bullet two, we can Algebraically isolate the unknown velocity because we know all the other variables:

1/2 mass of bullet 1 (known) * velocity of bullet 1 ^2 (known) = 1/2 mass of bullet 2 (known) * velocity of bullet 2 ^2 (unknown)
->
velocity of bullet 2 ^2 = mass of bullet 1 * velocity of bullet 1 ^2 / mass of bullet 2
->
velocity of bullet 2 = (mass of bullet 1 * velocity of bullet 1 ^2 / mass of bullet 2)^1/2
->
velocity of bullet 2 = velocity of bullet 1 * (mass of bullet 1 / mass of bullet 2)^1/2

This model is an estimate only and is sensitive to internal ballistic variables not captured in the model, e.g. different surface bearing areas, small different in bullet radii, etc. Nevertheless, I have found it to match real world results pretty well and use it in my bullet analysis as result.

It is just one of the pearls of wisdom from Bryan's "Applied Ballistics".
</div></div>

Got it. Must have missed that bit in the book. It's pretty clever.

 

[BryanLitz]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Got it. Must have missed that bit in the book. It's pretty clever.</div></div>

Pg 61 & 62 of the second edition. It's in the wind chapter, which is not obvious but this little tid-bit had to go somewhere.

 

[D_TROS]

Re: 130gr JLK by the numbers - evaluate my analysis

Conservation of energy perfectly applied.

This good read as I am currently doing a 260 build and have yet to decide on bullet in the 130 gr class...

keep the range report coming. You wouldnt happen to have any 130 bergers to test simultaneously would you? Prob not practical to work up 2 loads, just a thought tho.

Regards,
DT

 

[damoncali]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Got it. Must have missed that bit in the book. It's pretty clever.</div></div>

Pg 61 & 62 of the second edition. It's in the wind chapter, which is not obvious but this little tid-bit had to go somewhere. </div></div>

I guess I'll have to buy the 2nd edition, then!

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: D_TROS</div><div class="ubbcode-body">You wouldnt happen to have any 130 bergers to test simultaneously would you? Prob not practical to work up 2 loads, just a thought tho.

Regards,
DT </div></div>

We have tested Berger 130gr VLD. Before getting the JLKs (I had to wait 6 months for them), we worked up 130gr VLD loads for our 6.5x47Ls. 42.7grs of H4350. Deadly accurate and it was doing 3050fps from 26" barrels. Our analysis suggests the JLK is a superior design - comparable to the BCs of the 140gr tangent ogives bullets - but the 130gr Berger is right there with it, only a step back. Both are excellent, top match capable projectiles. The Norma 130gr is also an outstanding design - I have another buddy who swears by them and uses them out of his 260Rem. He has won a lot of matches with that Norma, more than I ever will with the JLK.

 

[elkregulator]

Re: 130gr JLK by the numbers - evaluate my analysis

What twist are you guys using? 8? 8.5?

Thanks-

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: elkregulator</div><div class="ubbcode-body">great tread...

What twist are you guys using? 8? 8.5?

Thanks- </div></div>

I have a 8 twist. My buddy who is shooting them has 8.5 twist. They are NOT long bullets (1.320") so you probably could shoot them in a 9 or even 10 twist barrels.

 

[mudvayne]

Re: 130gr JLK by the numbers - evaluate my analysis

This is great data! I shoot the 130 JLK out of my 6.5x47L. Only prob is for my actual drop data for a specific set of temp/alt/BP/Hum I have to set my G7 at .281 and the velocity at 2950 even though my chrono says 3040fps over 42.1 gr of H4350. I have a 29" Lawton 8 twist. Maybe my chrono is way off though too...I am supposed to drop 7.2 mils at 1000 according to FTE but real world is 7.4. I will apply the G7 of .303 and tweak velocities and see what happens! I will post some pics of some INCREDIBLE 1000 yard groups I have shot with this combo!

 

[Scimitar]

Re: 130gr JLK by the numbers - evaluate my analysis

My brother shot a 260 with that at 2935 fps and bullet drop to 1300 yds was a little less than JBM calculations. I ran it at a G7 at .307

 

[mudvayne]

Re: 130gr JLK by the numbers - evaluate my analysis

Good to hear...

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mudvayne</div><div class="ubbcode-body">This is great data! I shoot the 130 JLK out of my 6.5x47L. Only prob is for my actual drop data for a specific set of temp/alt/BP/Hum I have to set my G7 at .281 and the velocity at 2950 even though my chrono says 3040fps over 42.1 gr of H4350. I have a 29" Lawton 8 twist. Maybe my chrono is way off though too...I am supposed to drop 7.2 mils at 1000 according to FTE but real world is 7.4. I will apply the G7 of .303 and tweak velocities and see what happens! I will post some pics of some INCREDIBLE 1000 yard groups I have shot with this combo! </div></div>

Interested to hear any real world ballistic data. Post up those pics too...
I'm still shooting thru my stock of Bergers and haven't had a chance to load the JLKs yet.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scimitar</div><div class="ubbcode-body">My brother shot a 260 with that at 2935 fps and bullet drop to 1300 yds was a little less than JBM calculations. I ran it at a G7 at .307 </div></div>

That is very promising to hear. .307+ puts it ahead of many (most) of the 140grainers. Very promising.

 

[jrob300]

Re: 130gr JLK by the numbers - evaluate my analysis

James,

I just got some of the latest run of 130 JLK's. Mine are 1.340" OAL, not the 1.410" listed on the web site. Are the BC's you derived from the same OAL as these? Or did Swampy change the design recently?

John

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

John-

The short answers is YES, the estimated BC is for the 1.340" OAL.

I spoke with both Swampy and Bryan Litz on this, because my JLK 130s also arrived "short". Per those discussions I learned that Swampy is using the same dies on the ogives and boat-tails and that his surface bearing area is what is shorter. So the ogives, boat-tail, and I think meplat are all the same. According to Bryan Litz, if this is the case, the shorter surface bearing area should have little to no impact on BC. So we are sticking to the estimated BCs. The reduced surface bearing area however does have impact on things like internal pressure, velocity and down range accuracy (less bearing area = bigger chance of in-bore yaw/pitch).

I have supplied a dozen or so JLK 130s to Bryan and he has said he will test them and give us a better BC than we can do just using math. He said it might take some time to get that data collected, so I don't know when we will have that number.

I have not yet started a JLK 130 load, so I can't add much to my above analysis. However, I have a second buddy that started to shot them in his 260Rem; he is getting good results (3050fps-ish, vs his 140gr's at 2900). The first guy outlined above is still getting good results with his 6.5x47L using the 130 JLK, so I continue to think our math is close to reality.

good luck w./ you load development. Please post any good data you get.

 

[jrob300]

Re: 130gr JLK by the numbers - evaluate my analysis

James,

What powder is your buddy running? Is he loading into the lands to help mitigate yaw/pitch?

I've been using 43 gr. H4350 in Lapua .260 brass fired by Fed. 210's pushing the 140 Bergers, and not getting near the velocity others are getting (2780 fps, but I'm not seeing any pressure, but haven't loaded any higher either) from similar loads, but it shoots the lights out. Several 5 rd. groups now in the .2's and .3's. Part of the reason for trying the 130's is the low velocity with the 140 VLD's. Hoping they will run more than proportionally faster... QL shows I should be able to run up to 45 grains and still be under 61K psi. We'll see...

Thanks for the info. I'll see if I can't get out this week and at least get some load vs. velocity data and then go from there.

John

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

He is running H4350 in Lapua brass. I believe he is at 44.3grains of H4350. Don't know what primer. He has 28" barrel. He is running out of mags, so the bullet is jumping something like 0.03"

 

[jrob300]

Re: 130gr JLK by the numbers - evaluate my analysis

Thanks,

I'll load some up and report back...

John

 

[jrob300]

Re: 130gr JLK by the numbers - evaluate my analysis

Apparently I have a slow barrel. My 140 Bergers are running about 2780 over 43 gr. H4350 in virgin Lapua. 43.5 was starting to show pressure. Loaded up 130 JLK's from 43-45 gr H4350 and they run 2780-2940, but over 2900 show ejector marks on the case head. Lapua is some hard brass, so when I see ejector marks time to back off. QL shows that 45 gr load at 62K, so it correlates.

At sub-2900 I really don't see the point in shooting these over the 140 Bergers. The ballistics are just close enough that I don't care and I have a ton of 140 VLD's and a great load.

John

 

[bward]

Re: 130gr JLK by the numbers - evaluate my analysis

I've been doing some load development with the 130 JLK the past couple days. I hit pressure at 41.8 which was yielding an average velocity of 2870.

The load I settled on is 41.6 grains of H4350, Wolf magnum small rifle primer, and jumping the 130's 20 thousandths.

This load gave me an average velocity of 2841 with an ES of 4 FPS.

I haven't shot these to test the BC yet, but should be able to sometime next week.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bward</div><div class="ubbcode-body">I've been doing some load development with the 130 JLK the past couple days. I hit pressure at 41.8 which was yielding an average velocity of 2870.

The load I settled on is 41.6 grains of H4350, Wolf magnum small rifle primer, and jumping the 130's 20 thousandths.

This load gave me an average velocity of 2841 with an ES of 4 FPS.

I haven't shot these to test the BC yet, but should be able to sometime next week.</div></div>

In what cartridge and barrel length? Sounds like 6.5x47L.

From analysis I have done of existing load data published on net, I wonder if H4350 is the best powder choice. RL15 and Varget appear to be getting the 123s and 130s going at better MV w/o as much pressure as H4350 in the 6.5x47L. N540 and N550 also are potential powders.

I have done some downrange chrono work (one chrono at 12' and one at 200yds). I was getting 3000-ish 12' and 2730-ish at 200yds, which worked out to 0.58-ish G1 and 0.29-ish G7 at the environmentals we were shooting. This was out of a 28" 260Rem.

 

[bward]

Re: 130gr JLK by the numbers - evaluate my analysis

I forgot to put in my post, my results are with a 26'' 8.5 twist in 6.5x47. I was shooting the 123 through the same barrel before I picked up the 130's, and hit pressure at nearly the same FPS with H4350 and Varget. I don't care how much FPS I could pick up from RL-15 or RL-17, I won't use them. Been down that road of big velocity changes based on temperature, and learned my lesson.

 

[bward]

Re: 130gr JLK by the numbers - evaluate my analysis

Any word on some official bc's for this bullet yet? I've only been able to shoot it out to 775, but a G7 bc of .295 seemed to be what I needed to use to match my come ups.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

bward-
No word. I have not seen Bryan Litz around here in a while and I emailed him a few weeks ago on something else and haven't heard back from him. Hope everything is OK with him.

Two buddies of mine are shooting the 130 JLKs tomorrow in a tactical match with ranges from 100 to 800 yds so we will have a bit more field data on them (I'm spotting for them and shooting my AR-15 along side them at same ranges). I think they are using 0.290 G7 on there dopes. I will report results here.

 

[Jedi]

Re: 130gr JLK by the numbers - evaluate my analysis

i exclusively use RL17 in both my x47's
have done for about 2 yrs no issue with temp spikes, just shot a 197 7x @ 500 with my match rig
Dont cook em in da chamber helps much

 

[trebark]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">Two buddies of mine are shooting the 130 JLKs tomorrow in a tactical match with ranges from 100 to 800 yds so we will have a bit more field data on them (I'm spotting for them and shooting my AR-15 along side them at same ranges). I think they are using 0.290 G7 on there dopes. I will report results here.</div></div>

I am one of the guys shooting the 130JLK tomorrow. I am unsure of the BC I will use for the match (am working to crunch data to determine that number now). Thankfully, will have James 'the mathematician' there for technical assistance.

For those of you that want to crunch some data, here is my velocity data collected a few weeks ago...

<span style="text-decoration: underline">Velocity @ 12' from the muzzle</span>
12-1 3013
12-2 3032
12-3 3013
12-4 3021
12-5 3020

<span style="text-decoration: underline">Velocity @ 200 yards</span>
200-1 2688
200-2 2726
200-3 2721
200-4 2731
200-5 2737

<span style="text-decoration: underline">Atmospheric Data</span>
Temp: 85.4
Barometric Pressure: 29.46
Altitude: 414ft

All shot from this rifle: http://www.longrangehunting.com/forums/f53/my-260-mcr-59628/

 

[bward]

Re: 130gr JLK by the numbers - evaluate my analysis

I just looked at my notes again and .290 is the G7 that works for my data, not .295 as I posted above. Looks like .290 is what they are.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

Tactical match field report on the 130gr JLKs:

two shooters - one in x47L (26" barrel) and one in 260Rem (28" barrel) - shooting the 130 JLKs at 2940 and 3000 fps respectively. Excellent results from both loads, with many, many hits on steel at >600yds that splashed within 1-2" of each other. The shooter with the x47L hit a 4" steel circle at 802 to win a share of the bonus pool. Clearly, this is an excellent projectile for precision and accuracy work out to 1000yds. One shooter was using a G7 BC of 0.290 and the other was using 0.300 and we couldn't shoot/see the difference.

As such, until I hear something from Bryan on the "official BC" or we see something in the ER numbers (we are planning to shoot them at 1200+ yds at some point soon), I'm going to split the difference and use 0.295 G7 (or roughly 0.593 on the G1 model).

This analysis has been a lot of fun for me and I hope you guys have enjoyed the discussion. Thanks to all posters who contributed and helped me!

 

[RedGoat]

Re: 130gr JLK by the numbers - evaluate my analysis

BTTT for more info on the 130 JLK

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Goatphius</div><div class="ubbcode-body">BTTT for more info on the 130 JLK </div></div>

We won another match w/ them this weekend -- Team Sniper Competition, Mayberry MD. I have a certificate for a nice new Manners stock as result

And we ordered another 1500 of them from Swampy. I still don't have the ER range data (1200+yds), but its tracking nicely to the above calculated BC on every target we have shot at under 1000yds. JLKs, H4350 and Lapua brass (either 6.5L or 260Rem) are a very good load.

 

[clinto]

Re: 130gr JLK by the numbers - evaluate my analysis

im bumping this thread back up to see if theres been anymore progress with determining the bc of the 130jlk, did Bryan ever test these?

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

Well, we continue to use the 0.295 G7 and the bullet is working great with that number. Tracking nuts on perfect out to 1250yds (no data beyond). Lots of first round hits at 1000-1200 yds with that number, thru a 260Rem and a 6.5x47L. Highly precise as well, with little tiny groups no problem and not sensitive to seating depth (we load them AI mag length and go). We could not be happier with the bullet vs targets (don't use it hunting however - terminal performance not good).

 

[clinto]

Re: 130gr JLK by the numbers - evaluate my analysis

Thanks for the update, what powder are you using and what velocity?

 

[Bluegrass Tactical]

Re: 130gr JLK by the numbers - evaluate my analysis

I've recently switched to the 130 JLK's (pointed). To say I'm impressed would be an understatement.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: clinto</div><div class="ubbcode-body">Thanks for the update, what powder are you using and what velocity? </div></div>

Only have used one powder - H4350. I'm getting 2925fps from my 26" 6.5x47L. My buddy is running a 260Rem with a 28" barrel and he is at 3000fps.

Also, I remember that he successfully used the 130gr JLK to 1500yds this summer out in WY and it was tracking nuts on with our estimated G7 BC of .295.

 

[phxfa]

Re: 130gr JLK by the numbers - evaluate my analysis

tag

 

[JSF]

Re: 130gr JLK by the numbers - evaluate my analysis

James, how long were you able to use the 130 jlk before running out of room in the mag? Thinking about trying some vld's in matches but don't want to go through all the load development and then running out of mag room not far down the road.

 

[jbailey]

Re: 130gr JLK by the numbers - evaluate my analysis

JSF-
I'm not chasing the lands, so my OAL is staying constant at AI mag length, I think 2.850". It was jumping initially, don't know how much however, so its still jumping and still don't know how much. Precision is as good as ever, so I don't think the increasing jump is hurting them.

There is a negative update however - JLK increased the price of their bullets. I bought 2000 pcs of them back when this thread was started at $0.32/pc. JLK now sells them for $0.53 (65% increase! WTF?!?!). I'm not chasing that. So once my bucket of JLKs at $0.32/pc is gone, I'm moving in another direction. THUMBS DOWN.

 

[JSF]

Re: 130gr JLK by the numbers - evaluate my analysis

Thanks for getting back to me. I wonder if the Berger VLD's will perform the same without constantly fiddling with seating depth. I saw the new price and that is why I am looking at the Bergers. They blame it on a 50% price increase for jackets.

 

[psinclair]

Re: 130gr JLK by the numbers - evaluate my analysis

I haven't had a chance to "air them out" yet, but so far, so good...

I'm a big fan of 130's in medium capacity 6.5 cartridges.

 

[psinclair]

Re: 130gr JLK by the numbers - evaluate my analysis

In all fairness, the Berger's shot pretty well too....