[HN Gopher] At 4.4 miles, Wyoming team sets new rifle shot world... ___________________________________________________________________ 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] ___________________________________________________________________ (page generated 2022-09-23 23:00 UTC)