VLD seating depth

C

chino69

Guest
I ran into a little problem that I would like to share and see if anyone has had a similar experience.

I have a 1 in 7.5" Kreiger barrel chambered in 6mm BR with a .265 neck. Began working up loads using 105 grn. Berger VLDs with Varget. Found a decent node at 30.2 grns. but just knew the rifle was capable of shooting better. The bullets were touching the lands. Going into the lands opened the groups up.

I contacted Eric Stecker of Berger and asked for advice. Eric suggested I try seating .030 off the lands. I loaded .010, .020, & .030 off the lands. The five that were .030 off the lands did very well at 300 meters. Why is this?

I always thought the cardinal rule was to start at the lands and go into. Is there something unique about VLDs that is contrary to popular methods?
Chino69

p.s. Eric Stecker has always been helpful and informative.
 
My 6XC...

I have found that my rifle likes the 105 Berger VLD (pushed by 39.5 grains of H4350) into the lands enough to make a square mark. This is in a 8 twist Krieger chambered for the 6XC. Good shooting. James Mock

PS Every rifle has its own likes; so I would start at full jam and shorten by about .005 inch increments and find the best seating depth. Some rifles like the bullet into the lands while others prefer jumping.
 
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I have always jammed VLD's into the rifling in the past and that was the only way I could get them to shoot no matter what the cartridge or weight but as of late, I have found five guns that liked some jump. And in some instances, a lot of jump. I also noticed this was around the same time that Berger updated some equipment. Perhaps there is a correlation.....
 
VLD jump

goodgrouper said:
I have always jammed VLD's into the rifling in the past and that was the only way I could get them to shoot no matter what the cartridge or weight but as of late, I have found five guns that liked some jump. And in some instances, a lot of jump. I also noticed this was around the same time that Berger updated some equipment. Perhaps there is a correlation.....
Click to expand...

I've e-mailed Eric for an explanation and am awaiting. Personally, this kind of thing interests me. You've found the same phenomenon and there may be a correlation with Berger updating some equipment. When Eric responds to me, I'll post.

Eric, if you are monitoring this we can all benefit from an explanation.
Chino69
 
I have a longer-range hunting gun that likes 210 Bergers about .033 off the lands and likes them a bit more about .010 jammed. Absolute crap in between. ("about" being a necessary concession to the differrent measuring methods) I don't think this "phenomenon" is new. Uncommon, I guess. The lot of 210s I'm shooting now is, IIRC, a about a year old and therefore a newer lot, however. The quality of the chamber may have more to do with it than updated equipment. But if you want proof -- forget you read this reply. I'm only offering an anecdote.
 
We created our own monster.

When the VLD was first introduced in the late 80's Walt would receive reports that the bullets would not shoot well. During this time it was much more common in reloading to jump the bullets. Walt along with many other BR shooters knew that putting a bullet into the rifling could produce improved precision so this is what he recommended to those having trouble with the VLD.

In many rifles this change worked so we started recommending that everyone put the VLD into the lands. This is where the phase "VLDs are not magazine friendly" was born. To seat the bullet out to touch the rifling required a COAL that was too long to feed through the magazine in most rifles.

When shooters reported poor performance when putting the VLDs into the lands we concluded that not all rifles/barrels would shoot the VLDs.

This is where we made our mistake. The thing we ignored was that many shooters were very successful shooting the VLDs with a jump. It just so happened that these folks weren't calling with problems. For years we told folks "jam the VLDs" and that "VLDs are not magazine friendly." Today we know the truth.

The truth is that VLDs ARE sensitive to seating depth. VLDs shoot best in a given "sweet spot." For some this is jammed into the rifling while others find the best precision by jumping the VLD as much as .150.

This truth has become clear to us as the VLD becomes more popular as a game hunting bullet. Hunters with top quality rifles who have never jammed a bullet in their lives (due to problems this can create in the field) are reporting excellent precision. At first we thought this to be a lucky circumstance from those who made initial reports but then we started paying attention to competition shooters who were saying the same thing.

Our current published recommendation is to try the VLD at both .010 into and .010 off of the rifling. We are changing this recommendation. When shooting a VLD you will get the best performance at a COAL somewhere between .020 into the rifling or .150 off of the rifling. It is well worth the effort to find the right spot. If you do this, you will see why VLDs are so popular among those who do.

I do not relate this to a change in dies as this result occurs in all calibers in which we make VLDs. Shooters have been saying this for years but we just didn't stop talking long enough to hear them until recently.

Regards,
Eric
 
Eric,

You'll recall that I am one of the bunch who jumps VLDs (210s in my case). I'm pretty sure that prerequisites for the VLDs working with jump is that the chamber has a minimum diameter throat & that the ammunition is loaded with negligible runout. It probably is an advantage with molied projectiles, which are reputed to startup erratically from one to the next when the moly is (partially) rubbed off by the lands - that's what Boots Obermeyer has opined anyway.

John
 
I've never jumped bullets much, a non-believer me, I've felt that "jumping bullets was just masking other problems"............

I've been working up VLD loads for my new 6X47L and accidentally left my Wilson seater stem loose. The gist of it is that I ended up with 30 or so randomly seated bullets with up to 40 thou of jump. I was just starting to pull them (broke my kinetic puller) when my kid showed up and said, DUHH!! shoot 'em!!

So I did. I set up a line graph and mapped them for velocity variation over the chrono. An interesting thing showed up, the bullets GROUPED! (My line graph is a leveled line with hash marks, I measure for vertical offset....kindofa' "ladder test", but different)


As Eric mentioned, I fiddled with jumps up to more than a hundred thou....

I ended up finding a load at 40thou off that replaced my former load simply because the accuracy was "same" and the ES was (is) nothing short of incredible. I'm a convert........when it comes to VLD's I will now explore jump.

I AIN'T gonna' anneal though ;)

LOL


al
 
Berger 105 grn. VLD follow up

Eric Stecker said:
The truth is that VLDs ARE sensitive to seating depth. VLDs shoot best in a given "sweet spot." For some this is jammed into the rifling while others find the best precision by jumping the VLD as much as .150.

Our current published recommendation is to try the VLD at both .010 into and .010 off of the rifling. We are changing this recommendation. When shooting a VLD you will get the best performance at a COAL somewhere between .020 into the rifling or .150 off of the rifling. It is well worth the effort to find the right spot. If you do this, you will see why VLDs are so popular among those who do.

I do not relate this to a change in dies as this result occurs in all calibers in which we make VLDs. Shooters have been saying this for years but we just didn't stop talking long enough to hear them until recently.

Regards,
Eric
Click to expand...

Eric,
Thank you for the explanation. Just a little follow up to my original observation. As mentioned previously, I followed your recommendation of seating the bullets .030 off the lands with very favorable results at 300 meters last week.

Last night I repeated the test at 300 meters starting .030 off the lands and continuing by seating in .010 increments going further from the lands. At .040 from the lands I hit an even more accurate sweet spot with a five shot group. Moving on to .050 from the lands opened the group up so I'll stick with .040. This is good info. for those shooting VLDs.

As an addendum and in reference to one of the above posts #7, my loaded naked bullet runout measures <.001. I use a Wilson neck sizer and seater. I know the reamer used for my chamber was a Henricksen and the work was done by Clarence Hammonds. The components and gunsmith are top shelf and that is why I knew the rifle was capable of doing better when I first started load development.
Chino69
 
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Regarding chamber dimensions, we are asked often for recommendations. The consistent feedback we get relating to chamber dimensions is that there is little scientifically proveable consistency.

Recently, there was a well written article discussing a lead angle of 4 degrees being better for VLD bullets. Those who tried a 4 degree angle did not see much improvement in precision. In fact most who reported observed increased pressures that many felt were not beneficial.

I mention this not to suggest that 4 degree is better or worse but rather to use this example to suggest that the many factors affecting internal ballistics (dimensions, steel characteristics and smithing quality) can influence the results in ways that are almost impossible to measure and prove.

This is why tuning a load for best precision is so important. Many who do this find that each rifle/barrel has a favorite load. I don't expect that this statement is a surprise to anyone reading this post. The point I am making is that tuning is required because even a rifle/barrel that seems to be the same in every way has undetectable differences that influence load precision.

Another point I want to make is that it is generally accepted that things like tight neck chambers (as an example) benefit precision. I accept this as truth but even these chambers will require load tuning.

Regards,
Eric
 
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