The below video details the annealing of a Berger VLD to promote fragmentation at long ranges / low velocity.
For long range hunting, fragmentary wounding is important as a means to promote disproportionate to caliber wounding in the absence of high velocity. With conventional hunting projectiles, as velocity falls below 2400fps, wounding gradually becomes proportionate to caliber, noticeably so at 2200fps. Between 2200fps and 2000fps, many projectiles (especially core bonded and copper projectiles) expand to a diameter of around 8 to 9mm, creating a wound channel of around 8 to 9mm, resulting in slow bleeding and therefore, if the CNS is not destroyed, a very slow kill. To regain disproportionate to caliber wounding at low velocities, the projectile must be capable of shedding a large amount of its bullet weight, allowing a cluster of fragments to create wide internal wounding. However, this doesn't mean to say that a .22-250 loaded with a varmint bullet will get the the job done on a red / Mule deer with shoulder shot placement. The fragmentary cluster must be matched to game body weights, having optimum momentum. Those who wish to learn more about long range killing (which differs greatly from long range 'hitting' are encouraged to read the book, the Practical Guide To Long Range Hunting Cartridges
The VLD was once a highly fragmentary projectile but due to complaints of bullet instability, Berger decided to toughen up the jacket of the VLD in 2011, launching the orange box line of VLD hunting bullets. Unfortunately, the problem with instability stemmed from twist rates that were too fast, usually employed in magnums and often with excessive free bore, allowing the projectiles to enter the rifling ever so slightly off center. As I write these words, I have a 7mm WSM on my bench (Kreiger), bore dimensions are perfect (tested), twist rate 1:8, sending the 162 grain A-Max tumbling. The rifle is not a great deal better with the 180 grain VLD, no tumbling but no accuracy either. Understand this - the 1:8 twist rate is not always optimal and in the magnums, it can at times prove highly problematic.
For all of the above, what is done is now done. Long range hunters need to explore ways to optimize the VLD in its current form, hopefully Berger will optimize their bullet design in the future, a return to the old bullet? a plastic tip?, who knows. Berger now have a new blurb on their site, explaining the VLD is designed to penetrate 3" before fragmenting. Well, Its not really designed to do this. The VLD was initially designed to fragment on impact like any other bullet- even the tough Swift A-Frame does this, ensuring immediate energy transfer for fast, humane killing. Yet I cannot hold Berger's words against them. They made a good bullet, hunters complained, this is the result- a good target bullet. It is however unfortunate that current twist rate calculator programs seem more heavily focused on stability through the transonic barrier. These recommendations can have negative consequences and are somewhat removed from the reality of long range hunting. But this can really only be understood through a deeper understanding of the differences between long range competition and long range hunting (hitting versus killing).
Annealing (softening) is one method of encouraging fragmentation of the VLD, meplat trimming is an additional positive alteration.
So, use the video to explore annealing but do not discount meplat trimming (see Hunting Cartridges book for more info on trimming). If my clients can hit a yearling goat at 800 yards and beyond with a chest depth of 9" using a BC of .475 at an MV of 2670fps, I am sure many of you will be fine using for example, the 7mm 180 grain VLD with its BC reduced from .684 to .600-.630 launched at 2900fps and higher.
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