shouldazagged
New member
The only thing I really want to know is what movie this character was "expert adviser" on. So I can avoid it.
Ballistics & bullet drop, hollywood style???
- Thread starter wogpotter
- Start date
On this web page is a video of a long spiral football pass in slow motion. The ball does not keep its original orientation but follows the flight path, just like an arrow would.
Spin stabilized bullets do this also, including artillary fired at high angles.
If a bullet or artillary shell is spun too fast, it stubbornly resists this orientation change and is "overstabilized", this results in a reduction of range and accuracy as the shell finishes its flight flying sideways.
http://www.sciencekids.co.nz/videos/sports/perfectspiral.html
Actually, I ran a ballistics table for 175gr SMK at 2600fps/muzzle (~nice M1A LC/match) zeroed at 1,000yds,
the table showed the arching bullet to still be 19.5" high at 975yds -- dropping in to zero at the req'd 1,000.
You can get a chart sense of that by looking at TaylorForce's Post #2 above.
Still, ...a foot & a half drop over 75ft run ain't that much -- angle-wise, that is.
(a 98mpg fast ball drops almost twice that distance from pitcher to catcher)
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45auto : as much is that is correct , I don't think you could be any more wrong . Now if the ball was travailing at 2700fps when it left Tom Brady's hand . Went 1000yds and never got more then 15 or so feet of the ground you may have something there . A 175gr MK with a muzzle velocity of 2700fps will still be traveling at 1200fps or 400yds per second at 1000yds .If the bullet never gets higher then 20 feet off the ground . There is now way it even gets close to 45 degrees little lone almost vertical .
Mehavey is pulling out the scientific calculator on my comment of "pretty steepe angle". So if "pretty steep" is up for debate, the simplistic way to look at it is angle of ascent and angle of descent since it is easier to figure than all the degree changes in a parabola. Angle of ascent is roughly 3.8 degrees and angle of descent is roughly 5.8 degrees. That is a change of 65% between the two, so I don't know if that qualifies as a "pretty steep angle" change or not? I never meant to imply that bullet was going to punch oblong holes through a target at 1K.
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Inv Tan (146/14400)=5.808 degrees (can't figure out how to put the symbol up there). Passable at some math, suck at figuring out computer keyboards. Like I said, I took a simplistic approach to doing the math because I didn't want to try and figure out the whole percentage of angle change along the parabola.
Obviously the picture isn't to scale.
Obviously the picture isn't to scale.
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I'm talking angle of approach/descent for 146" of drop in 400 yards or 14,400" (not 1400", sorry for the typo and thanks SSA). Like I said my math is only passable on my best day. However I never made it past College level algebra so my trig is a little rough.
Finding angle of approach/descent
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Angle=57.3°/radian*146in/(400yd*3ft/yd*12in/ft) = 0.580958333°
(decimal places... Bah! Who need`em)
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I used to do this on my slide rule while having to keep mental track of the exponents.
Nowadays, Mr Excel makes this stuff so easy a CavePerson can do it.
(My non-Excel brain is in hibernation for later in the Spring.)
(decimal places... Bah! Who need`em)
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I used to do this on my slide rule while having to keep mental track of the exponents.
Nowadays, Mr Excel makes this stuff so easy a CavePerson can do it.
(My non-Excel brain is in hibernation for later in the Spring.)
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Now you know why I was going by dim memories from my dinosaur brain. I looked at my sliderule and realized all I still knew how to do with it was multiply and divide. I could have pulled my old notes out from when I was doing trig and integral calculus and tried to refresh my memory but that would take me a couple of weeks if I had a good day. You forget a lot of things in 50 years if you don't use it every day.
I would have had to take into account drag, speed reduction and increased rate of drop at each increment and I'm not up to it. I asked my buddy the class math whiz and he just told me to get....well it was impolite. Apparently he has forgotten a lot of this stuff to.
They put fuzes in the base of artillery shells because a fuze in the nose would be destroyed when the shell hit the first obstacle. You want the shell to penetrate a defense (e.g., armor plate or earth) and explode on the other side. If the fuze is in the nose, it will either be destroyed and not function at all, or detonate the charge on impact with no penetration.
If you want to get an idea of a real trajectory, one yard in 1000 yards would be drawn to scale on an 8" wide sheet of paper as .008" or a barely visible bump in the pictured line of flight.
Jim
If you want to get an idea of a real trajectory, one yard in 1000 yards would be drawn to scale on an 8" wide sheet of paper as .008" or a barely visible bump in the pictured line of flight.
Jim
ndking1126
New member
Wow, that's a lot of math to start the day off with! Interesting reading though.
Art Eatman
Staff in Memoriam
The old original '06 172-grain boat-tail load was claimed to have a max range of some 5,100 yards. My understanding is that a max-range shot means an angle of elevation of around 40 degrees. Logical, then, that the "re-entry" angle would be around 45 degrees. )
Well everyone seems to agree on "dropping vertically down on the target's head" isn't at all realistic , which was my original question. Wether its 45, 25 or 1.2 seems kind of irrelevant.
I am surprised that someone who charges quite a large sum for training should be so innacurate though. If I'm paying a couple of grand for training I'd like it to be accurate & good, not something fictional I could get watching old western reruns on TV for nothing.
I'm not about to name the person, or the shewtin' academy in question as I don't want to run foul of the boards policies. I will say thats one place I'd delete from my "possible sites to visit for advanced training" though.
I am surprised that someone who charges quite a large sum for training should be so innacurate though. If I'm paying a couple of grand for training I'd like it to be accurate & good, not something fictional I could get watching old western reruns on TV for nothing.
I'm not about to name the person, or the shewtin' academy in question as I don't want to run foul of the boards policies. I will say thats one place I'd delete from my "possible sites to visit for advanced training" though.