As it happens, when someone on a chat list to which I subscribe mentioned that the “regular reason” people want certain rifles was to “kill people from a great distance from a place of concealment” I happened to be in the process of watching the “Sniper 101” series of videos available on YouTube. Very interesting stuff. The fellow who produced the videos (Rex) goes into great detail. GREAT detail. Most videos are 20-30 minutes long and I’m on part 62 currently. (Rex also scores his own soundtrack.)
Folks with a Hollywood education likely believe that to “kill people from a great distance from a place of concealment” all you need to do is buy a Big Rifle, attach a Big Scope, insert a Big Bullet then aim the crosshairs at the target (through a hole you cut in the hotel window with a glass cutter) and pull the trigger. It’s more complicated than that. There’s science involved, lots of science.
Years ago, when the local Gun Club shooting range was in a different location, the longest shot we could make was about 300 yards. I enjoyed ringing the 300 yard gong, though in hindsight, I was woefully ignorant of ballistics and long distance shooting technique back then.
I consider “great distance” to be anything over a couple of football fields. The Sniper 101 series is about “extreme long distance” shooting. One video has Rex shooting at 1388 yards. (He missed, but corrected for it later.)
In recent years, I’ve been honing my handgun skills (mostly Glock) and playing with my Uzi. But I’ve been thinking about some rifle bench rest shooting down the road and started watching “Sniper 101”. Very interesting stuff.
For example, when a rifle is fired, the bullet, if you could see it in extreme slow motion, would be revealed to start and stop several times. Upon ignition of the shell’s primer, there may be enough pressure created to dislodge the bullet from the shell casing. It would travel forward just far enough to encounter the bore of the rifle, then stop, the friction being too much for its then very low momentum. Once the powder charge starts burning (pressure vs time is an almost bell-shaped curve), the pressure reaches a point sufficient to start a bullet down the barrel to the point where it encounters the rifling — the lands and grooves that cut into the bullet so as to impart a stabilizing spin. At this point, the bullet stops again because the pressure has not yet built to the point where it can overcome the friction of the rifling. But that occurs soon enough and the bullet it again accelerated down the barrel to the muzzle.
Now, you’d think that at the point where the bullet leaves the barrel, it has attained the maximum velocity of its short trip. In fact, however, the pressure wave of hot gasses exiting the barrel behind the bullet continue to push the bullet and accelerate it even more. And it all happens in a little over a millisecond from ignition of the primer.
Rex talks about barrel harmonics and nodes. And how the powder charge can affect those harmonics and consequently, the size of your groups. (More powder is not always better.)
There’s geometry and calculus. Science. Lots of science. If I’m immersed in the Gun Culture up to my knees, Rex is up to his eyeballs. You’re probably familiar with windage and elevation adjustments. Rex goes into compensating for barometric pressure, temperature and humidity. The official Army manual has it exactly backwards regarding humidity, saying that it slows a bullet when the opposite is true. Turns out that water vapor is less dense than air.
Entertaining and educational stuff. I doubt I’ll ever need to “kill people from a great distance from a place of concealment” but this video series will help me ring the gong.