The "dumbing down of America" - shooting uphill or downhill.

[Jim Watson]

A related matter I have wondered about.
The gravitational effect can be calculated or approximated, but how about the effect of time of flight? The bullet will take time to reach the target depending on its velocity along the actual line of fire, not the horizontal distance. Will that not at least partly counteract the reduced gravitiational effect?

 

[d2wing]

I was thinking the same thing Jim.

 

[MCMXI]

A related matter I have wondered about.
The gravitational effect can be calculated or approximated, but how about the effect of time of flight? The bullet will take time to reach the target depending on its velocity along the actual line of fire, not the horizontal distance. Will that not at least partly counteract the reduced gravitiational effect?

dmancornell mentioned this earlier. If you look at the figure in my first post, G_para would be in the direction of the bullet's velocity shooting downhill, but opposite to the bullet's velocity shooting uphill. G_para is basically zero for a horizontal shot. Therefore, the time of flight (over the same linear distance) would be different for all three situations.

And since you want to be exact, why not factor in the sine projection of gravity and its positive (downhill) or negative (uphill) effect on bullet velocity?

BullfrogKen has mentioned Bryan Litz and his book a number of times. As Bryan Litz mentions, most ballistic programs don't take this into account or the change in air density when shooting uphill or downhill. For a sniper in Afghanistan shooting at a target 1000 yards away at an angle of 45°, the elevation change for the bullet is over 2,100 feet. In a mountainous region, air density (density altitude) can change drastically. For some people in some situations, this stuff is very important.

Here's a link to the AMU "pro tips" feature where they discuss uphill/downhill shooting on Shooting USA.

http://www.shootingusa.com/PRO_TIPS/USAMU4-11/usamu4-11.html

 

[sig220mw]

I know to aim a little lower on up hill or down hill shots because I have missed such shots in the past. Having then read and talked about it and through field experience I have learned to be able to kill game in this situation.

But this thread is giving me a head ache.

 

[benzy2]

BullfrogKen has mentioned Bryan Litz and his book a number of times. As Bryan Litz mentions, most ballistic programs don't take this into account or the change in air density when shooting uphill or downhill. For a sniper in Afghanistan shooting at a target 1000 yards away at an angle of 45°, the elevation change for the bullet is over 2,100 feet. In a mountainous region, air density (density altitude) can change drastically. For some people in some situations, this stuff is very important.

And if that shooter in Afghanistan is learning how to shoot at 1000 yards at a 45* angle on shootingusa I think there are bigger problems at hand.

While I won't try to argue that to some it is important and that it was technically incorrect, you continue to ignore the fact that it's a TV show meant for the masses, most of which don't shoot more than 100 yards at the local range. Maybe they could reword their script, or maybe you should let it go. In the big picture, to the masses, which a TV show is targeted, the rough guess is more than close enough and the exact physics of it are smart to leave out. It's the outdoor channel, not the NASA channel. If their physics lessons aren't exact I wouldn't be surprised. Again, it's television.

 

[Art Eatman]

Thing is, for 90% of Bambi shooters, anything less than 30 degrees won't matter at all. Inside 300 to 400 yards it won't make much difference until you get on past around 45 degrees.

Odds are, folks who hunt mountain country and may commonly expect shots of 300 yards or more already know all this stuff.

This ain't the first time the horse has strayed from the corral...

 

[MCMXI]

benzy2 and Art .... good points.

 

[35 Whelen]

I'll go simpler still, when shooting up or downhill, hold a little lower on your aimpoint.

You took the math right out of my mouth.

When I was a young lad, I used to obsess over the technical data in the back omy Dad's old Sierra manual. Regarding shooting uphill or downhill, I finally realized that for it to really matter, the target had to be a REALLY long ways off (too far in other words), or at a really steep angle. So, if I decided if there was any doubt, I'd just hold a little low.
In the ensuing 35+ years of hunting here in Texas and in the mountains, I've yet to have to worry about it.
35W

 

[Sport45]

Where it really mattered for me was when I was younger and used to shoot sparrows (just sparrows mom, really ) out of trees with my BB or pellet gun. When you sight in a low velocity rifle on horizontal targets you can shoot suprisingly high when aiming up into a tree.

 

[Andrewsky]

Time of flight is very, very slightly higher if you are shooting uphill or downhill at a reasonable angle like 30 degrees compared to shooting tangent to the surface of the earth (0 degrees).

So if you just say, well, the bullet needs to go 500m to hit that target up on the hill, and the angle of elevation of 30 degrees, you can approximate your adjusted, "equivalent" range to target at 500*cos(30), which is 500*(.87) = 433m. So you should act like you're shooting at a 433m target and aim a bit low. The target really is 500m away from you at an angle of 30 degrees, but you need to pretend like you're shooting at something 433m away from you in a level ground situation.

This approximation method ASSUMES incorrectly that time of flight is identical for the same distance no matter what the angle. It takes very, very slightly longer for the bullet to do the same distance uphill. I'm talking, if your velocity is 3000 meters per second using the same dimensions in my second paragraph above, the time to target is like .1666 seconds if it's level, and .1667 seconds if it's at 30 degrees. So, very, very slight difference in time of flight in that case.

 

[Andrewsky]

If you aim the gun straight up 90 degrees, gravity has zero impact on the point of impact of the bullet.

At 60 degrees, the bullet gets half of the g.

At 30 degrees, it's 87/100ths of the g.

At 0 degrees, it gets all of the g.

But you can't just equate the situations of 0 and 30 degrees perfectly because you can multiply the 0 degree one by cos(30). The time of flight is different. Like the OP said, it's actually the component of g that matters, not the horizontal component of distance to the target. You need to know the component of g and the time of flight.

 

[Pete D.]

wow, a lot of people are jumping on the "who cares" bandwagon on this one...if you don't care, don't post.

You have to be careful about that.....
It kinda depends on what in the OP that you care (or don't) about.
The discussion of the dynamics is interesting.
The point, though, of the OP as stated in the subject line was about "dumbing down" of America. The inference there is that if a person doesn't understand the exact, as opposed to the approximate, then that person is dumb. Not true. This is a fairly sophisticated discussion and not being able to follow it does not make a person dumb. That idea deserves attention and comment.
The TV presentation simply reflects the need to simplify.
Pete

 

[Leaky Waders]

"But there's no surprise there, most kids in school couldn't even point to Iraq on a map of the world."

These 'kids' are the ones in the combat zone...they all know to aim a little low on inclines and declines.

LW

 

[Still Shooting]

Quote:

And since basic newtonian physics is not even covered in high school, do you really expect the exact math to be covered on a TV show?

The dumbing down of America is illustrated by this statement. When I was in High school in the early 60's, basic newtonian physics was absolutely a part of both math and science classes.

 

[Sergeant Sabre]

I'll go simpler still, when shooting up or downhill, hold a little lower on your aimpoint.

Simpler STILL: Hold where you would usually hold because the difference is completely negligible in nearly every hunting situation.

 

[jdh]

It was a segment on a high density TV show. He had about 45 seconds to make his point. Not nearly enough time to completely explain the process.

Simple solution: Use the force Luke, Use the force.

 

[biff47]

So if you were a full-time sniper, then you would probably be able to do the math in your head AND have your observer double-check your math. You probably would have lots of practice as your position might often be on the high ground.

In my life, I draw the line at 3 digits of long division. In my shooting, I know that gravity affects bullet drop less dramatically when the angle of fire is up/downhill. I don't use math-heavy trig in my everyday life, so it just serves me better to aim an inch low at 150 or 2" low at 250 and call it good. <100 yards, I don't care.

Not exact, but it achieves its purpose. If math were a muscle that I used more often, the real equation wouldn't be heavy lifting.

I think it would have been better if the show would have explained the math behind the reality. The general population doesn't appreciate the hard science behind ballistics, I think. But TV shows sometimes (surprise, I know...) weights the entertainment heavier than the informative content.

I guess an equivalent complaint might be that hunting shows never show the hunter gutting his own elk and carrying it out in 4 trips back and forth to his truck 3 miles away, in the rain.

 

[grubbylabs]

Ahhh roger that, whats your vector Victor?

 

[dmancornell]

The dumbing down of America is illustrated by this statement. When I was in High school in the early 60's, basic newtonian physics was absolutely a part of both math and science classes.

For another example, just look at the endless arguments over AR-15 buffer weights and their supposed effects on felt recoil. Newton's second law and linear momentum were covered, as I recall, in the second class of high school physics, which by 1995 was considered an honors science class in my school and not a graduation requirement.

 

[Art Eatman]

Ya want dumbing down? Okay, to drift: Back around 1994, I was in Vegas for a trade show. Had the TV news on. There was a clip showing a 3rd grade teacher and her class. She was all proud that the kids had learned the times table, all the way up to ten times ten.

In the fall of 1941, in the 2nd grade, I learned the times table to twelve times twelve.

IIRC, we were parsing and diagramming complex sentences in the 4th grade. I don't think it was third grade, but it was for sure a long time back.

My grandfather taught math in Austin High School. I have one of his old trig books, from 1932. First half, Plane Trig. Second half, Spherical Trig. Spherical Trig shows why Great Circle routes are shorter for shipping--but you guys know that already, don't you?

And English literature, junior year of HS: "TB or not TB, that is the congestion..." and a bunch more of Jakesbeer's stuff. Worthwhile, though; "Neither a borrower nor a lender be," is good advice that a bunch of folks ignored to their detriment.

 

[Pete D.]

progress

When a student went to a University back in the 14th century, he studied "the liberal arts of
arithmetic (Calculus hadn't been invented yet. No physics. Newton wouldn't write the Philosophiae Naturalis Principia Mathematica until 1687.) , geometry, astronomy, music theory, grammar, logic, and rhetoric. The primary emphasis was on logic."
(Grammar, logic and rhetoric are the three ancient arts of discourse.) Do we study discourse any longer?
The prospective student would have spent six or so years acquiring the degree of Bachelor of Arts.
Both the Scholastic and the later Humanist models of university study pretty much demanded some facility with both Greek and Latin. Newtonian physics - written in Latin.
I studied Latin in High School. I'm hard pressed to say that I benefited from the experience.
How many of y'all studied that way? Are we dumbed down because we didn't?
Pete

 

[John_galt]

My daughter is in kindergarten - learning Latin. My 3rd grade daughter is learning Western Civilization history this year, the tests are essay, graded for content, spelling and grammar. Not all schools are dumbed down. The third grader uses the Latin she's has learned, and is still learning, to breakdown words. Her vocabulary is much better because of it.

But a rant because a 45 second TV package didn't explain the trigonometry fully? Life must be really frustrating on a daily basis if that is a serious annoyance......

 

[Pete D.]

yes

My daughter is in kindergarten - learning Latin.

As much as I did not enjoy one moment of my own experience with Latin, that note is refreshing to read.

Pete

 

[Art Eatman]

Looks to me like we've covered the uphill/downhill stuff enough for this session. It's gonna show up again, for sure. Next time, discuss it in Latin.