Berger Tips for Loading VLD Bullets
The folks at Berger Bullets have just released an interesting technical bulletin that describes methods for optimizing bullet seating depths with Berger VLDs. The document explains how to find the OAL “sweet spot” for VLDs in your rifle. Interestingly, while VLDs commonly work best seated into the rifling .010″ or more, Berger’s research indicates that, in some rifles, VLDs perform well jumped .040″ or more. This is a significant finding, one that’s backed-up by real-world testing by many shooters.
The key point in Berger’s report is that: “VLD bullets shoot best when loaded to a Cartridge Overall Length (COAL) that puts the bullet in a ‘sweet spot’. This sweet spot is a band .030″ to .040″ wide and is located anywhere between jamming the bullets into the lands and .150″ jump off the lands.”
CLICK HERE to download Berger VLD Tuning Tips
Writing in the report, Berger’s Eric Stecker observes: “Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).”
For target competition shooters (for whom it is practical to seat into the lands), Berger recommends the following test to find your rifle’s VLD sweet spot.
Load 24 rounds at the following COAL:
1. .010″ into (touching) the lands (jam) 6 rounds
2. .040″ off the lands (jump) 6 rounds
3. .080″ off the lands (jump) 6 rounds
4. .120″ off the lands (jump) 6 rounds
Berger predicts that: “One of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005.”
OBSERVATION and WARNING
Berger may definitely be on to something here, and we applaud Berger’s testers for testing a very broad range of seating depths. However, we want to issue a STRONG WARNING to reloaders who may be inclined to try the 4-step method listed above.
Be aware that, as you load your cartridge progressively shorter, putting the bullet deeper into the case, you will be reducing the effective case capacity dramatically. With smaller cases, such as the .223 Rem and 6mmBR, moving from .010″ into the lands to .080″ and .120″ off the lands can CAUSE a dramatic pressure rise. So, a load .010″ into the lands that may be safe can be WAY OVERPRESSURE with the bullet seated .120″ off the lands (i.e. .130″ deeper in the case, the difference between .010″ in and .120″ out).
To illustrate, using a QuickLOAD simulation for the 6mmBR cartridge, moving the bullet 0.130″ deeper into the case can raise pressures dramatically. With the Berger 105 VLD seated .010″ in the lands (with 0.220 of bearing surface in the neck), and a charge of 30.0 grains of Varget, QuickLOAD predicts 60,887 psi. (This is using ADI 2208 data, and a 5500 psi start initiation value). If we move the bullet back 0.130″ further into the case, QuickLOAD predicts 64,420 psi (even after we drop start initiation pressure to the “default” non-jammed 3625 psi value). The 64,420 psi level is way higher!
| Cartridge & Load | COAL | Jam/Jump* | Start Pressure | Max Pressure |
| 6mmBR, 30.0 Varget Berger 105 VLD |
2.354″ | +0.010″ in lands | 5500 psi | 60,887 psi |
| 6mmBR, 30.0 Varget Berger 105 VLD |
2.324″ | -0.20″ JUMP | 3625 psi | 59,645 psi |
| 6mmBR, 30.0 Varget Berger 105 VLD |
2.264″ | -0.80″ JUMP | 3625 psi | 62,413 psi |
| 6mmBR, 30.0 Varget Berger 105 VLD |
2.224″ | -0.120″ JUMP | 3625 psi | 64,420 psi |
* As used here, this is the variance in OAL from a load length where the bullet ogive just touches the lands (first jacket to barrel contact). Loading bullets to an OAL beyond that point is “jamming” (seating bullet into lands), while loading to an OAL shorter than that is “jumping” (seating bullet away from lands).
NOTE: This is only a software simulation, and the real pressures you encounter may be different. But, the point is that moving the bullet 0.130″ further down in a 6mmBR case can raise pressures more than 3,000 psi! Therefore, you must employ EXTREME CAUTION when moving your bullets that much in a relatively small case. Remember that going from .010″ jam to a very long jump will probably increase pressures in your cartridge so you MUST adjust your load accordingly.
Similar Posts:
- Berger Article on Cartridge Overall Length and Base-to-Ogive
- How Cartridge Overall Length (COAL) Affects Pressure & Velocity
- How Changing Cartridge OAL Can Alter Pressure and Velocity
- Cartridge OAL — How It Affects Pressure, Velocity, and Accuracy
- How Changes in Cartridge OAL Can Alter Pressure and Velocity
I think that there needs to be some standardization of the term “jam”. According to my understanding, jam is the longest loaded length (best measured off of the ogive) that can be chambered in a particular rifle (with the neck tension that will actually be used for the ammunition), without the OAL being reduced by closing the bolt. I realize that this is not the main point of the article, but the way that the term is used in it will, I fear, lead to further misuse of the word and confusion.
In short range benchrest, many find that jam is quickily found without special tools and because of this, is a useful point from which to reference seating depth. It has been pointed out to me that longer, high ogive number bullets like VLDs may have a greater tendency to stick in the throat when this method is used, lessening its usefulness for these applications, but since I believe that the use of the word jam to designate a particular seating depth came out of short range Benchrest (based on my observation of published use of the word) I believe it appropriate to stick to the original meaning. We should therefore refer to loaded lengths that just touch the rifling as touching, those that are extended a distance in reference to that length as so much longer than touch, and those that are referenced to jam as at jam, if that is the case, or so much shorter than, or of jam if they are between jam and touch and jam is being been used as the reference point.
Boyd is right that many short range benchrest shooters use the term “Jam” to refer to the maximum load length you can seat a bullet before it pushes back into the case. However, that is by no means a prevailing definition, and if you look at the reloading discussions for the majority of shooting disciplines, the much more common understanding and usage of “jam”, “jammed”, and “jamming” is to refer to bullet seating past the point of initial bullet jacket to rifling contact. Under this interpretation, seating a bullet to any OAL that engages the rifling is “jamming”. That, I believe, is the most common application of the term, and it is the one Eric Stecker employs in his commentaries above.
I would also suggest that defining “Jam” as a singular “max” point is not particularly beneficial because that then requires a different third term to describe bullet seating beyond the point of initial bullet jacket to barrel steel contact. Furthermore, the functional utility of “Jam” as a definitive end point is questionable because our testing showed, fairly conclusively, that this “Jam” point varies based on neck tension, the condition of the bore surface, and whether the bullet is coated or “naked”. So, “Jam” is never a true, absolute maximum, but is conditional on other loading variables.
Conversely, the point of initial jacket to barrel contact is NOT dependent on neck tension (or bullet coating), and, when measured with the right tools, is very repeatable. You’ll find that trying to get repeatable measurements of “Jam” as the absolute max OAL point (let’s call that “Max Jam”) is very difficult when using longer bullets (for long-range shooting) or stronger neck tensions (appropriate for gas guns). When you try to measure “Max Jam” with strong neck tension or longer bullet, you may find the bolt won’t close or the bullet sticks in the rifling. Either way, this renders your measurement efforts useless.
As Boyd and others employ the term, “JAM” can be useful, as an indexing point, so long as it is repeatable. But since that “JAM” OAL can change simply with a little more neck tension, that definition really is not particularly helpful for most reloading applications.
We know that jam is barrel bullet and neck tension dependent. These variables also effect tune. Consider that those who use this term as I have described it shoot in a sport that is considered to be the peak of accuracy achievement, and I have never heard any active participant complain of a problem with this approach. They know how it works. Change a relevant variable and the jam length will change. That is why I note barrel, bullet, and bushing size in my load notes, and generally size brass just before the ammunition is to be fired, because I am aware of the effect aging of sized brass has on seating force. I think that this term came from Benchrest and began to be used by others who did mot fully understand what was meant by the term that they had read or heard, thus causing the lack of linguistic precision that I mentioned in my earlier comment.
Of course, one should choose the seating depth reference that is best suited to his particular situation and equipment, but to dismiss something that evidently works well for a whole group of shooters who are as a group the standard of 100 – 300 yard accuracy may speak more of lack hands on experience with their sport than any deficiency in their methods.
Maybe now the “common wisdom” of jamming VLD’s into the rifling, ie: interference fit, will finally be questioned. My old Sinclair Catalog/Reloading Primer told me every barrel is different about what it likes as far as “bullet jump” is concerned, and once discovered, that jump remains the same regardless of bullet. True.
FYI, none of my barrels like the VLD’s jammed. They most often come in at .020-.025″ off the lands.
BTW, someone at Nosler once told me the Ballistic Tips shoot best .040-.050″ off the lands. At first I was very skeptical, but after a day of testing at the range, I was surprised to learn he really knew what he was talking about.
To have an honest test of this method, one must adjust the charge weight to balance the pressures for all the test seating depth loads. Would the author please disclose the source of the 5500 start pressure for the “into the lands” group? Quickload recommends 10,825 start pressure for this configuration. Your example is just a bit higher than 1/2 their recommendation. I fear this variation could present chamber pressure issues in some unfortunate circumstance.
EDITOR: Read my full review of QuickLOAD software: http://www.6mmbr.com/quickload.html
This includes “power-user tips” for best results when working with the 6mmBR cartridge. I have found, empirically, that with 100-108gr bullets, this 5500 psi value works best to describe actual observed velocities and the delta in observed velocities between “in the lands” seating and “off the lands seating”. I have also discussed the default 10.8K start pressure value for seating “in the lands” with the creator of QuickLOAD and he acknowledges that this is a “rough variable” that needs to be adjusted in light of observed conditions. He’ll say right up front that “10.8K is too high for high-bc bullets and hand-lapped barrels” and he also conceded that his software probably “exaggerates the effect of engaging the rifling”. If you set the start pressure at 10,800 psi for a 6mm 105-grainer seated in the rifling in a 6BR, you’ll end up with projected velocities that are way too high and predicted pressures that would trash the brass. But if you enter 5500-6000 psi, the vel numbers will jive with your chrono read out and the observed healthy condition of the brass.
I’ve personally done the experiment, with a 6BR, of moving a 105-grainer from .015″ in the lands to .035″ jumping… a change of 50 thousandths. It was very clear that this caused an increase in pressure marked by: enlarged ejector mark, very visibly enlarged primer crater, higher chron’d velocity, and stiff bolt lift. In a 6BR, for my own safety, I would definitely reduce a load that worked ten-thou into the lands if I moved the bullet 80 thousandths or more deeper into the case.
Of course, with a large case, such as the 30-06, the change in pressure that occurs when you seat a bullet 100 thousandths shorter is very different.
I may have different observations here but I have never really observed a significant pressure difference between jamming bullets into the lands and jumping them – even long jumps. With the 6mmAR and the 6mmAR Turbo line of cartridges (close to 6BR capacity cases) I load bullets for magazine feed that have to meet magazine OAL length where the bullets sit back in the case quite a bit hogging up valuable case capacity. These bullets have to jump quite a bit to hit the lands and I frequently use the same loads as I use for long line single load shooting where I seat the bullets in the lands .010″ and I don’t really see a pressure difference at all. I suspect it takes very little pressure to move the “jumping” bullet and push it to the lands and that the encroachment into the powder capacity there has little effect on pressures since the pressure really jumps up only after the bullet moves forward and engages the rifling and pressures build to force the bullet to engrave onto the rifling.
Robert Whitley
EDITOR: Robert, when you go from in the land to a little jump (say 10-20 thousandths), the pressure will initially drop. I’ve added some additional values to the chart. But when you push deep into the 6BR case, the pressure rises again. Jumping 80 thou or 120 thou (as suggested by Berger) CAN give you pressure problems in a short case if you’re starting with a max load seated long, then pushing the bullet deep into the case. I want to make sure that people understand this. Safety first.
I certainly agree with the EDITOR that safety should be the primary and the first concern when doing any type of load testing.
That being said, I just recently had done tests shooting Berger 105 VLD’s mag length in a couple different AR’s where they sat way back in the case when loaded magazine length and had to jump over .100″ to hit the lands and I did not see any pressure issues with that. So that’s where my comment above came from. If others have experienced different results with jumping bullets quite a long ways, I cannot comment on that other than to say follow the cautions of the EDITOR and err on the side of milder loads and caution when you experiment.
Robert Whitley
Thanks to the Editor for his generous reply to my comment, and thank you for suggesting I read your fine article. It really helped me find a more effective attitude for the way I use Quickload and appreciate what an excellent resource it is. I hope to use the forums to discuss variations in results and get some ideas of how to address them.
The included info from Berger appeared during the Shot Show which was news to me and a place to begin again looking for the “sweet spot” for my 270 Win. Not a great long range cartridge but it shoots everything else I have tried so why not. Long story short, last week I discovered exactly what has been referred to above relative to erratic pressures. Turns out 55 gr. of RL-17 using a 140 gr VLD will shoot without incident at all four suggested bullet positions as will 54 gr. loads of the same powder. Not so with 54.5 gr loads, though, which resulted in .120″ off the lands being okay, but at .080″ the first round resulted in a blown primer and the second in a completely destroyed case. The third was not attempted nor were .040″ or seated at the lands loads. Most surprising, curious and potentially dangerous. I can’t imagine how one might predict the onset of such conditions due to the fact these extraordinarily high pressures occurred pretty much in the middle of what had already(?) been demonstrated as “safe” – 50 to 56 gr loads – in previous testing with the same cases, primers, powder and bullets. I truly appreciate the warning contained in the Forum … maybe I’m not nuts and it is something all should heed. RL
rblong,
With your best interest at heart, all those RL17 loads you cite are probably potentially over max. By potentially, I mean the same over max load will not exhibit pressure signs with every shot. Small arms ammo is very inconsistent, ie: unpredictable, when you are at, or slightly above, the max charge. There is a point where every round would drop the primer, or worse, but that’s at +max+ charges. Indeed, some can be very conistent, and accurate then, KA-BLOOEY!
Case in point, I tested 100 rounds of 223; same load, same gun. Ninety eight cases came out looking normal and were subsequently reloaded, but segregated. Two cases ejected their primers bigtime, with a very enlarged pocket and lots of fouling. I had to assume all 100 rounds were over max. Again, small arms max pressures don’t always give themselves away.
The moral is: the visual/physical evidence available to us is insufficent to reliably detect over max pressures. Even the most sophisticated calculations are not completely reliable. The only way you can hope to accurately and consistently determine pressure is with a pressure gun, and there are margins of error for them, too.
P.S I’d like to think I could come up with all the above on my own. But no, I was listening to William C. Davis, Jr.. I came to him with all the “common wisdom” I had gleaned from the range BS sessions, and went away humbled.
Kent:
I truly appreciate your input. I was simply following a procedure I had developed for myself 25 years ago when I was busy figuring out how to make the 22 CHeetah “work” properly. Doing so took a great deal of determination and perhaps a certain amount of risk because for a couple of years hangfires, blanked primers and erratic ignition seemed to be more common than not. 1800 rounds later it showed itself to be as predictable as a 220 Swift, however. After working through the Cheetah and subsequently developing loads for several other calibers without ever having such a dramatic display of pressure as happened last week, it may well be possible that many of my loads are border line in the pressure department. None of them exhibits any visible sign of pressure during my normal shooting which is why I was so surprised. I now have something else to pass along in the next reloading class I teach. Thanks again.
Rob Longsworth
rblong,
I’ll confess to occasionally submitting to temptation and loading beyond recommended charges, and getting away with it. But truth is, I can’t tell the difference between a 3500fps hole, and a 3300fps hole. There are a few safe exceptions, depending powder/primer lots, brass, rifles etc., but it’s safer to go with the factory recommendations because they use pressure guns. Even then, there are exceptions.
Also, when we fail to follow the rules, the guns and smiths we have today provide us with a significant margin for error.
want to try Berger bullets in my 22.250 what the best for coyotes will be shooting lot of open country. am shooting 55gr sierra now. 1:14 twists
Reloading data for 6.5 Creedmoor with Berger 130gr & 140gr Match Target VLD bullets. When is your reloading manual due for sale to the public?
Thanks for the great article! I tried this form of load dev and it worked great for my hunting rounds (Barnes TTSX 165 in .308). Great way to find the right OAL to ogive and then can work on the powder side (since I generally know the ballpark for XBR 8208, from a lot of load testing.) Now I can fine tune the powder load. Thanks again for this great method.
Gotta love all you experts who continue to keep on knocking on heaven’s door (or the other place) – keep it up and one day blammo you will be picking bits of bolt out of your face and skull.
Recommended maximums are set for a good reason and just because it didn’t go catastrophic does not mean it will not…. one day.
Jamming rounds into the lands increases the break pressure necessary to defeat the distortion of the guilding metal and underlying core on ignition during initial pressure build up as the lands dig in and engrave the projectile.
Being ‘off’ the lands allows for initial movement which means an increase in the bullets inertia rather than a zero value when jammed. This allows for the engraving resistance to consume a little of that initial rising peak pressure.
Interesting no details shown here about velocity.
Thanks for the commentary on Jam definition, very helpful, I get the feeling people use the term lightly and it should not be as jamming creates pressure spikes.
Need load data for Berger 115VLD
Have a rem. sps 308 tactical. I want to try some of your 168 VDL hunting bullets but i am limited to making the loaded cases fit in the magazine.I would like to try them .o25 off the lands but no way.
Any suggestions @ what might be a good powder.
Any information would be greatly appreciated. I have replaced the hogue stock with a a HS precision.
&mm ruger No1B 7mm rem mag 180gr VLD hunter best grouping is with bullet seated .118 off lands. Thats a lot of jump
I just got my first order of Bergers and Lapua brass, in 6.5 CM, and, studying, came across this page. At first I was excited about such an easy way to find the sweet spot…….but then the over pressure warnings scared me off.
Can’t the ladder test of ten or so rounds, each with about two grains more powder, find the right node for the rifle in use?
Or am I confusing diff elements of bullet tuning?
I’m currently shooting 1/2 MOA at best at 300, and am seeking to make that the rule rather than the exception. Once I do that I feel I will be ready to take it out further. My goal is to be able to paper plate five rounds at a 1000.
Oops…..
Shooting the RPR in 6.5 CM, my baby.
I’m going to be loading Berger bullets for the first time. Wondering if anyone has experience and or data for either or both rounds regarding charges and or seating depths.
First round is 28 Nosler 180g VLD using Retumbo in a Nosler model 48 with 26” barrel.
Second is 300 Win mag 190g VKD using H4831SC in a Remington 700 with 26” barrel.