Is the Berger 105VLD the 115 killer?

[HPMike800]

I was looking at the new BC's in the Berger literature handout at SW LR Regional and noticed that the 105VLD is 0.532 and the 115VLD is 0.545. The differance is only 0.013! I don't know what it is for the DTAC but I'll bet it's less than both being a tangent ogive. Running the numbers on JBM as long as the 105 is 75fps faster than the 115 the drift is the same.

I've seen the 105 shoot very well at 1,000 in the BR cartridges and it's a proven flexible bullet. Not really finikey at all. Whereas many complain of the 115's not being able to shoot.

So in the XC and 243 Imp cartridges why aren't folks running the 105's 150fps faster than the 115's. There should be a ballistic advantage to it.

Or are they? Will the 105's standup to 3150 - 3200fps?

What are your thoughts.

 

[Bob3700]

Mike,

I shoot the 107 SMK and 105 Berger at 600 yds in a 6mm BRX. Driving those bullets just a tad over 3000 fps. Actually, the 107 SMK has given me better X counts than the Berger so that is what I am using.

For 1K shooting, I use the 115 DTAC in the 6mm MMX (Tubbs first version 20 degree shoulder) and drive them a little over 3000 fps.

My experience is that the 115 DTAC is much easier to get to shoot accurately than the Berger 115. Tried both and stuck with the DTAC. Again, X counts were the determining factor.

The DTAC has the ballistic advantage over the 107/105gr bullets. It may not be a whole bunch but at 1K everything counts.

From matches I have competed in, the DTAC will shoot so close to a 142 SMK that I wouldn't want to bet on the difference. Now realize that I shoot in the mid-west and we don't experience hurricane like winds as can be found on some ranges out west. So that is what I am basing my statements on.

If I shot in high winds all the time, my tune might change.

Bob

 

[GermanS1]

Mike, that's a great question and I've been wondering about it myself lately. As you know, I shoot the 115 Berger at 1000 yards from a 1:7.5" twist Krieger and the 105 at 500 and 600 from a 1:8" twist Bartlein (both are 6XC chamberings).

Using H4831sc, I am at roughly 3050 fps with the 105 and 2950 fps with the 115. I'm not at all sure that the 115 delivers any real advantage, but it's been a very accurate and consistent bullet for me at 1000 yd. so I'm hesitant to change.

I'm trying to book a few extra 1000 yd. days for us at Ben Avery and if we get those days, one of my planned projects is to fire them both side by side to begin to make some comparisons. If I had to shoot my 1:8" twist barrel at 1000 with 105's today, I wouldn't feel at any particular disadvantage but I want to try to put a little experience behind that intuitive feeling.

 

[Laurie]

Mike,

an interesting observation - I hadn't realised their BCs are so close. Using Bryan Litz's G7 BCs and the Berger Bullets PC Ballistics program with German's MV actually gives the 105gn VLD the smallest drift since it's running a full 100 fps faster.

There's not a great deal in it though on this data - 72.4" for the 105, 73.88" for 115 VLD and 75 for the DTAC in the classic 10 mph wind at 1,000. In practice, wind shifts / misreads of the wind will normally run at less than the equivalent of 10mph at 90-degrees, so that 2.6" / quarter-MOA difference becomes a lot less to the point where you wouldn't see any noticeable difference.

I suspect that the ballistics tables never give the full story though especially at extreme ranges, and there is the actual group size of each bullet at this distance to consider too, wind effects aside.

Bob's point about finding the 115 DTAC easier to tune compared to the VLD is pretty well the received wisdom on this side of the Atlantic too. There is a feeling the 115 VLD's length pushed the jacket too far so far as stresses are concerned, the DTAC's heavier jacket and slightly shorter overall length working out better. Maybe Berger has updated its jacket from those days, but the reputation has stuck.

I haven't tried either 115 so far but will get the chance later this year in a new 6XC that's on the way. I bought a bunch of DTACs ready for this rifle, then found an elderly secondhand box of 115 VLDs that I bought out of curiosity.

Laurie,
York, England

 

[Bob3700]

German,

Like you, I cannot empirically tell you that one is better than the other. My BRX will shoot the 107 SMK right at 3020 fps from an 8T Bartline 5R bbl that is 31 inches long. It will shoot all the Xs I can hold.

The 6MMX is also a Bartline although it's 7.5T and the same 5R at 31 inches length. I see the same sort of performance from it, Xs are all dependent on my ability to hold em.

Using the H4831sc, the 115 DTAC will chrono the same velocities at the 107 SMK out of the BRX. 3020 fps.

I have shot both at 1000 yds and have to say that my gut feeling is that the 115 is better in the wind. Wind here in the midwest is relative as we don't get the velocities you see out west. My usual plan is to shoot the BRX when the wind is at lower velocities and the MMX when it picks up.

All that just might be a mind game I play with myself to help generate confidence. But in the end, you shoot what gives you the best score and the bullet/load you have confidence in.

Finally, I feel that when taking either 6MM to the line at 600 or 1K, I am not at a disadvantage to any other competitor. They really shoot well.

Bob

 

[oneflyer]

Berger's webpage states the 105 VLD as .493. Where does one find the .532 105 VLD's?

 

[Bob3700]

I think that Berger just recently down graded the BC of that bullet. Do a search on that bullet as I think that Eric from Berger had a post with the explanation.

Bob

 

[white121]

Berger has seemed to change the BC on their bullets about every 6 months over the past year and a half. I wonder if they have done more extensive testing to find out the true BC? I'm not knocking the bullets as I shoot them and they are great!

Shaun

 

[sparker]

The revised BC figure for the 105 is to reflect the larger meplat due to using a larger knockout punch.

 

[HPMike800]

German: That’s great. Hopefully the feed back is good. Let us know.

It really doesn’t matter if DTAC 115’s are more forgiving than 115 VLDs since the idea is to avoid using both of them. One of the benefits is to use more forgiving bullets in general. I just never here people say I can’t get those damn 105’s to shoot. What this tactic does rely on is that they will shoot at 3100-3200fps and that they will hold together.

The data is from the Berger bullet handout. The thick jackets (resulting in a lager meplat) on the new 105VLD’s caused the reduction in BC. The “hunting” bullet is still a 0.532 BC. I think Berger may have been premature on thick jacketing this bullet. Was it really having blow up problems? A 0.493 BC kills this whole idea and the bullet for that matter. I suppose they could be pointed up to restore what was lost. (For those that are willing to do that)

If your gun just won’t shoot VLD’s for some reason the wind drift of the 107/108’s is the same as the DTAC 115’s if you can shoot them 100fps faster. In most target cartridges this should be doable. All calc’s from JBM using the Litz bullets.

If you can shoot 115’s at the same MV as the 105’s then the advantage is going to the 115’s. I can’t really see this as the general rule however.

 

[Flybuster]

I might be wrong, but I think Eric admitted that the new 105 vld has a lower b.c. than the 108. While my main bullet was the old 105 vld for long range, I am switching to the 108. The 108 has provided the greatest precision between both bullets in my couple of years with them, but wind deflection a was obvious difference at 1000 yards, the 105vld had the advantage there. It may be that the 108 does tune better than the vld.

 

[watercam]

John Whidden has won often shooting the 105s in .243.

 

[Bob3700]

Mike,

I agree with your thoughs on the 105 VLD. My BRX will shoot them well and the load was not hard to find. Actual "On Target" results with the 107 SMK have been just a bit better for me.

With the 105 BC being down graded, and putting some work into the SMKs, I actually think the green box bullets are the better choice right now. My rifle produces smaller groups and the BC on the reworked SMK is better.

That will probably change as I am sure Berger recognizes this as well and is working to revise the 105 gr VLD design.

I do go to the larger cartridge when I shoot the 115 DTAC. The extra boiler room is required to get the velocity up to where the larger bullet can show it's better BC. The down side to the DTAC is that with the longer bearing surface, your bbl life is probably not a lot better than a 6.5x284. High perf has high costs.

The boys down south like shooting those 105s out of 243 and 243AIs with their MV of 3200 fps. Can't imagine how often you change out a bbl on those guns. That is why the interest in Salt Bath Nitriding. Trying to get better throat life!

Bob

 

[johara1]

David said in a past posting on here that the new 115 DTAC BC was over .585. Now if thats true is a no brainer......run the numbers at 3050 to 3100 out of the 6mm sx 6mm slr or what ever you want to call it or the 6mm cm.......jim

 

[HPMike800]

Might be a good idea to call John and find out if he has blow up problems.

The 0.532 105VLD is still being produced it just comes in an orange box.

I like and shoot the 107/108's in my BR too. I found that I have to shoot a slightly milder load since they gave me pressure a little eariler. In fact I plan on killing off this barrel with them.

If you use the Litz data on JBM the 115DTAC@3000 is the same as the BGR115VLD@2990. From that I would think the DTAC is about BC=0.542. That's just it, the numbers come up better with 105's with just a small bump in MV.

 

[GermanS1]

Bob, even with 115's and H4831sc my barrel life on the 6XC is well over double what I used to see in a 6.5-284 (which I haven't shot in a few years).

I agree with Mike that the thick (and lower BC) 105 is not particularly of interest since I've never seen a normal (now "hunting") 105 blow up even when pushed at over 3000, although I haven't shot them over 3100. When I tested RL17 at 3300, it was with Sierra 107's but I don't use that powder in my loads, I just did that for the product test.

I think one conclusion we can draw is that the two bullets, at their respective MV's are actually very close in drift and it's more important to develop one of them into an accurate and reliable load for your rifle than to worry about what Laurie properly described as insignificant differences in paper drift figures.

 

[js223]

There seems to be a misunderstanding about the 105 from a few of the people here. As Mike correctly points out, it's *only* the thick (Target) version 105 VLD that has a lower BC now. Eric Stecker from Berger explained that they changed the nose on the thick jacket one. The (Hunting) 105 VLD is still the same as it was with no change, and has a .532 G1 BC.
Suggest those who are confused go to Berger's site and read Eric's blog on this subject.

 

[HPMike800]

I completely agree German. These small diffrences are next to meaningless in real world target shooting. It does matter however in that the gun really has to be built for one or the other. So the shooter must have a high degree of confidence in the choice - hence the math. The purpose of the thread is two fold:

1. Is the 115 a bullet for which there is no target need? If you can shoot 105-108 bullets 150fps in the same cartridge, it may be the case. Assuming the bullets will shoot at said velocity of course.

2. To coax out anyone shooting 105-108's at 3100-3200fps to see how well they do. We haven't seen any of that yet.

 

[GermanS1]

Mike,when I was testing RL17 I shot one match (500 yd) with Sierra 107's at 3280 fps. The score was 600-39X, but I didn't continue with that load (or RL17) because I was worried that I would blow up bullets at those speeds.

I called the range yesterday and was able to book us a few extra 1000 yd. days so we'll have a chance to try some of these thoughts on targets instead of keyboards pretty soon!

 

[Bob3700]

Mike,

I believe that people who are shooting the smaller cases (BR based) are/will have the best results with the 105-107 gr bullets. You just can't get enough MV with the small case and the 115s to improve performance.

Now if you are talking about going to larger cases, then the 115 makes a lot of sense and gives you an advantage. Full blown 243 cases can easily move the 115s enough faster than the 105/107s to have an advantage on target. The DTACs have a heavy jacket and don't fly apart. This thick jacket issue arose cause there were those shooters driving the 105s fast enough to come apart before they got to the target. That was not happening at 3100 fps!

Those who are doing it and are successful don't broadcast the advantage that they believe they have found. They just go win matches with it.

Bob