Friday, December 16, 2011

Praxis: Shooting at angles. Excellent instructional video.



pdxr13 said...

Because the first shot is the most important one.

Good explanation of height estimation error affecting range estimation, and correcting by using known-width, rather than height, because it won't change by your high-or-low perspective. Eraser is a very good prop.

Laser range finder is awesome, until your batteries are dead. Mil-dot scope, optical range finder, range card don't need batteries, just a little user know-how.

Useful-accuracy for an angle finder is +/- about 3 degrees (example division used was 10 degrees), so we don't need precision measuring lab standards, more like jr. high school geometry plastic protractor with a weight on a string for vertical reference.

Speed of use is important, 'cause that critter isn't going to stand there all day.

Anonymous said...

Many rangefinders available today automatically calculate "true ballistic range" (TBR) for you, depending on the angle. As long as your battery is good you don't have to worry about the trig.

Bad Cyborg said...

I am SOOOOOOO glad that I can use the markings on the parallax adjustment to give me range to target. Now I just need to find a simple, affordable way to measure angle up or down. From there a couple of entries into a programmable calculator should provide hold over/under. I could even program it to read in mils for my mil-dot scope.

Now if I could get a link for hold over/under based upon data for my rifle, I would be cooking.

Borborygmus said...

Still got it wrong. The path difference or drop is always perpendicular to the horizontal(time) line and not perpendicular to the bullet's original angle. Re-do the video so the presenter doesn't sound like an empty spray paint can.

Anonymous said...

Bullet drop is always down and the amount is always related to the time of flight. This video presents the correct first order approximation to the exact solution, and it's the same shooting up or down. The second order approximation is that the time of flight doesn't just depend on range to the target but also whether it is up or down - shooting up slows the bullet and shooting down speeds it up. In most cases the second order correction is not needed to stay on man-sized targets at reasonable ranges.

Shy Wolf said...

A carpenter's angle finder would be a great tool for finding the angle. A one-piece unit, usually made of plastic, it's about the size of a palm and easily fits in a shirt pocket. Will give 'roof angle' measurement in degrees from zero to 90. Cost, about $10 now due to inflation.
WV: 'grace'- something we all are in dire need of.