[HN Gopher] At 4.4 miles, Wyoming team sets new rifle shot world...
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At 4.4 miles, Wyoming team sets new rifle shot world record
Author : bkohlmann
Score : 72 points
Date : 2022-09-23 20:34 UTC (2 hours ago)
(HTM) web link (cowboystatedaily.com)
(TXT) w3m dump (cowboystatedaily.com)
| spywaregorilla wrote:
| Is this an engineering challenge or a marksmanship challenge?
|
| Like... Could you just fire the gun, then put the target where
| the bullet went an fire again and say its mission accomplished
| because the real goal is just setting up a gun that stable and
| precise and deterministic?
| Enginerrrd wrote:
| Both, combined with quite a bit of luck.
|
| >Like... Could you just fire the gun, then put the target where
| the bullet went an fire again and say its mission accomplished
| because the real goal is just setting up a gun that stable and
| precise and deterministic?
|
| No... slight variations in wind and atmospherics across that
| distance change too rapidly and significantly to make that
| viable. (Also, you wouldn't need to, you'd just adjust the
| windage/elevation on the optics and/or fancy rifle mount.)
|
| Also the when the bullet drops from supersonic to subsonic
| speed, there is a non-deterministic kick that it receives which
| dramatically reduces accuracy beyond that distance.
| adrianpike wrote:
| Both - the firearm has to be incredibly precise, but you also
| have to take into account wind and air density to get that much
| accuracy, and a big portion of marksmanship is accounting for
| those. Knowing that you'll have a temperature change over a
| body of water, and how to adjust for that, for example.
| TylerE wrote:
| I wonder what the rules are? _Naval_ rifle guns have achieved
| hits beyond 20 miles in combat
| Retric wrote:
| Looks like +/- 2 inch accuracy which is well beyond naval guns
| at 20 miles.
|
| Custom guided artillery shells could probably hit that kind of
| accuracy at significantly longer ranges, but pure ballistic
| weapons simply aren't designed for extreme accuracy at range.
| jonah wrote:
| This reminds me about the Ukrainian Snipex Alligator sniper rifle
| I read about recently. It uses 14.5-millimeter heavy machine gun
| rounds and it's claimed to be able to penetrate 10mm steel armor
| at 1,500 meters.
|
| https://www.popularmechanics.com/military/weapons/a41283557/...
|
| https://snipex.com/alligator
| RajT88 wrote:
| I was surprised to see a big red "BUY" button on that page.
| Surely it can't be that easy?
|
| Upon clicking, "This Account has been Suspended. Contact your
| hosting provider for more information."
| chasd00 wrote:
| It's not that big of a deal really. A guy in the high power
| rocketry hobby club I'm in has a 20mm cannon. It's a single
| shot anti tank rifle basically. It's pretty much impossible
| to use it in a crime because of how gigantic and heavy it is.
| ketzo wrote:
| I don't know if that's supposed to be comforting, but
| "Don't worry -- this weapon is _way_ too large and powerful
| for someone to use in mere petty crime! " does not exactly
| put one at ease
| ptomato wrote:
| funnily enough, a 20mm anti-tank rifle _was_ used in a
| crime back in 1965, to bust open a vault at a Brinks
| facility.
| exabrial wrote:
| Two quotes I thought were noteworthy:
|
| > traveling at a downward angle and about 600 feet per second as
| they reached the target zone.
|
| That is incredible. Some BB guns don't even fire horizontally
| that fast
|
| > Regarding it taking 69 shots to hit the mark, with all the
| variables that had to be taken into account, "we were thrilled it
| was so few," Humphries said.
|
| To give an idea of how difficult this is....
| akerl_ wrote:
| Just to clarify, I'm pretty sure they're saying that the bullet
| left the muzzle at 3,300 fps and had decelerated down to 600
| fps at time of impact, not that it was moving vertically at 600
| feet per second. So the fact that it was moving faster than a
| BB gun isn't really shocking.
| mod wrote:
| After four miles, it's a little shocking to me.
|
| And I'm into shooting sports.
| hinkley wrote:
| Assuming the bullet is traveling on a purely ballistic
| trajectory, no weird aerodynamics, calculator is saying it will
| have a vertical delta V of -235 m/s at 24 seconds. So more like
| -700 ft/s. But friction is real so I don't know the real
| number.
|
| I'm quite surprised they didn't have the barrel pointed higher.
| Was the shooter on a plateau?
| timcavel wrote:
| themodelplumber wrote:
| > "When a bullet is in flight for that long, you have to take
| into account the rotational speed of the earth. What you're
| shooting at isn't going to be in the same place it was 24 second
| ago when you pulled the trigger."
|
| Wow. Impressive work! I also noted the pitch differential between
| scope and barrel :O
| rabi_molar wrote:
| It's essentially a little bit similar to a mortar shell launch
| I suppose, at that distance? Reminds me of the fun I had trying
| to do ultra long distance shots playing Gunbound (South Korean
| MMMORPG that was similar to Worms) online. Very impressive.
| sbaiddn wrote:
| Impressive, indeed [1], but its the easiest of the corrections
| they had to do. Its a standard classical physics question and
| has been included in artillery calculations since at least the
| late 19th century.
|
| [1] Id imagine that a bullet, being so light compared to a
| shell, is more affected by fluid flow than the coreolis force.
| That the correction was needed means they nailed the far more
| difficult fluid problem.
| teaearlgraycold wrote:
| https://www.youtube.com/watch?v=tXVcXmyKpeI
|
| > At this distance you'll also have to take the Coriolis effect
| into account.
|
| COD did it first
| gbrindisi wrote:
| 7.08 km
| [deleted]
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