Brian, great article. I am a mechanical engineer and enjoy the technical discussion and your understanding of and experience with the subject. The scaled comparisons is exactly the type of information I need to assist in selecting a chambering begin my next rifle build.
I am just starting long-range target shooting at Quantico MCB in an effort to increase my long-range hunting ability. To that end, I have been practicing with a 300 WSM
that I built as a compromise between elk hunting and target shooting. I shoot 190 SMK because of seating depth with my current throat and the fact that I want the rounds to feed from the blind magazine. I could increase the throat so that I can achieve max powder capacity with current 220, 240 gr VLDs, but I still want to chamber my favorite 180gr hunting bullets. I have made a study and also found that the heavier bullets are lacking in their form factor. I am glad to see that I arrived at a conclusion that is agreement with your more extensive experience and expertise.
After a couple and practices and shoots, I have been bitten by the target shooting bug and am now considering a purpose built rifle for target shooting competition. I was considering the 6.5 x 284 however the 7mm WSM
is also interesting.
I make the following observations and comments with the understanding that Brian's article was directed at target shooting and not hunting. However another member made some comments/inquiries about downrange performance on game so I would like to weigh in on the hunting aspect of the .30 cal versus the smaller calibers while keeping in mind that the subject of bullet terminal performance on game is, due to lack of specific testing and data, a somewhat subjective and anecdotal driven subject.
While a smaller caliber bullet can certainly be selected for a high BC and launched at the required velocity to compete with or exceed .30 cals in the kinetic energy department downrange there are other factors to be considered. Terminal performance on game such as elk, moose, or bear is in addition to kinetic energy, heavily dependent on momentum which is a function of mass x velocity where mass has equal contribution to the momentum function value. If a lighter bullet strikes a bone with the same kinetic energy strikes as a heavier bullet but with less momentum, typically the lighter bullet will damage the bone, but deposit most of it's kinetic energy to the bone and surrounding tissue at that point since velocity is dramatically changed while the heavier bullet will likely damage the bone and continue on to the vital organs with more overall energy due to its' larger momentum value.
Thanks again Brian for the excellent article. I look forward to your next article.
P.S. I am glad to hear that girls make excellent shooters as I am trying start my daughter into the sport.