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 (up to 90%), 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.
The VLD was once a highly fragmentory projectile but due to complaints of mid air bullet blow up in 2010, Berger decided to toughen up the jacket of the VLD in 2011 with the orange box line of VLD hunting bullets. Unfortunately, the problem with mid air bullet blow up stemmed from twist rates that were too fast, usually employed in magnums and often with excessive freebore, 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.
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.
Annealing (softening) is one method of encouraging fragmentation of the VLD, meplat trimming to 70 thou and sacrificing BC for fast clean killing is another method.
So, use the video to explore annealing but do not discount meplat 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. And for those wondering why not simply use the A-Max if the BC is going to be reduced, the answer lies in the bullet weights available in the VLD line. As an example, the 7mm 162 grain A-Max cannot deliver the same level of performance on large bodied deer as the original 180 grain VLD or altered / optimized versions of the newer orange box 180 grain VLD.
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