Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
Point of hors d'oevre

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Parallax Free Laser Gunsight

Like an SLR camera that fires deadly projectiles.
  [vote for,

Every gun that appears in hollywood movies seems to have a laser pointer on it. It seems simple; put the laser dot on the zombie's head, pull the trigger, zombie head explodes. But what about at close range where the parallax effect means that the bullet will impact well above the dot? Or at long range, the bullet will be under the dot. Before you start yelling, "parallax free" holographic sights solve the parallax problem that red dot sights have on your end, but can still be off from the target.

If you haven't guessed by the tagline yet, my solution is to take the mirror assembly from a SLR camera and mount it at the front of a gun barrel at a 45 degree angle, with a laser pointer aimed vertically into the center of the mirror. SLR mirrors are capable of moving in thousanths of a second so when you pulled the trigger the mirror could move out of the way of the bullet and pop back into place so that the laser will always indicate the exact impact point of the bullet, regardless of range (not taking bullet drop into consideration of course).

DIYMatt, Aug 22 2011

"BLADE" http://articles.jan...United-Kingdom.html
Never leave home without some (we don't). [8th of 7, Aug 22 2011]


       This idea would correct parallax, but that is the least of the problems. A laser sight mounted immediately above the barrel and parallel to it will produce accuracy to the limit of shooter.   

       Bullet drop is a much more significant issue.
MechE, Aug 22 2011

       Here is an example where this would be very useful: You need to shoot the lock off a door. It is a small target, and you are only a couple feet away. A normal laser pointer attachment would miss completely.
DIYMatt, Aug 22 2011

       //Bullet drop is a much more significant issue.//
Won't the SLR's autofocus mechanism automatically compensate? (the anemometer on the fore-sight will take care of windage)
AbsintheWithoutLeave, Aug 22 2011

       Hmm, aren't you supposed to correct for range - and doesn't that apply to all types of sight? Sure, we could spend 5 minutes of each movie watching as everyone carefully preps all their gear, looking up range-tables and cross-checking their gun-range notes. But, in the same way we don't see the main protagonists of an action film making their breakfast, many of these things are edited out for dramatic effect.   

       But, going back to bullet-drop, that's something you need to significantly factor into your ranging calculations, not to mention height differences (if the shooter is way up on a rooftop, aiming downward for example) windage etc.   

       Laser sights are probably only really effective for the psychological impact they impart. Plus, it's clearer visually in film to show that the snipers have a 'bead' on the target if said target is painted with a series of red laser-dots.   

       Though I'd expect the laser sight to only really be of use to people who don't have time to aim properly, and need to be able to shoot at a second's notice and needs a rough indicator of where their bullets are going to land. Range is likely to be relatively short, i.e. indoors. Otherwise, you'd have time to use optic sights that didn't provide a convenient light-source for the enemy to aim back at.
zen_tom, Aug 22 2011

       Simpler, shirley, to rack up the laser power and eliminate the need for the bullet?
MaxwellBuchanan, Aug 22 2011

       Incidentally, the laser sight could also be used as a rangefinder, and could compensate for bullet drop accordingly. (I presume this is baked.)
MaxwellBuchanan, Aug 22 2011

       Shirley mooch symphlee to home-in a laser-coded- infrared-emission- seeker bullet, w/o a winking me-roar moost definitelee !
rotary, Aug 22 2011

       Perhaps what you need is a differently-shaped dot. One dot at the highest point of the bullet trajectory, one dot at the lowest point inside the gun's range, with a series of lines between showing gradation.
RayfordSteele, Aug 22 2011

       Laser pointers are now so cheap it would be possible to incorporate a laser pointer in the bullet. Thus, the laser beam would go from the laser-pointer-bullet, out of the gun barrel and illuminate the target. I know you're about to ask: "How cool would this look if someone was firing a machine gun at night and all the bullets had these laser pointers in?" - well, the answer is "Very".
hippo, Aug 22 2011

       //You need to shoot the lock off a door.// Shotgun with Hatton rounds. The most likely result of shooting a lock with a pistol or rifle (besides injury to people on both sides of the door) is a lock with a slug of lead imbedded in it that is now completely frozen and unable to move at all.
MechE, Aug 22 2011

       ...and the other feature of having laser pointers embedded in bullets is that if you saw someone's sighting laser being pointed at you, and the light suddently became slightly blue-shifted then you'd know that the bullet was travelling towards you very fast.
hippo, Aug 22 2011

       In Zentomia, all the laser-bullets use facial recognition (cross referenced against the Hippolandian phonebook) and are thus able to project the appropriate names directly into the eyes of their intended targets.
zen_tom, Aug 22 2011

       // Shotgun with Hatton rounds //   

       "Blade" linear conformable cutting charge.   


       <smug grin>
8th of 7, Aug 22 2011

       // Every gun that appears in hollywood movies seems to have a laser pointer on it. //   

       That's because Hollywood loves fancy guns. I once saw about three minutes of a movie (before I changed the channel in disgust) where a character was lugging around a Franchi SPAS-12 (the world's most needlessly complicated shotgun) that the props department had somehow fitted with not only a laser-sight/tactical light combo, but also a 40mm objective BSA scope. Why? Because it looked high- tech and intimidating. In real life, laser sights have limited tactical applications and a couple of serious drawbacks.   

       The real challenge with buildinig a device like you've envisioned would be making it resilient. Every accessory you stick on a gun has to be able to sustain repetitive shockwaves as the recoil of the shot is absorbed by the frame.
Alterother, Aug 22 2011

       // absorbed by the frame //   

       Transmitted to the frame. The shock is absorbed by the firer, unless they're not holding on properly, in which case it tends to be absorbed by other bits of the immediate environment, and you'd better have a DAMNED good explanation ready for the Sergeant Armourer when he asks where all the dents and scratches came from ...
8th of 7, Aug 22 2011

       // Transmitted //   

       Thank you. Much better terminology.
Alterother, Aug 22 2011

       Max's up-rated laser suggestion is great apart from the drawbacks.   

       What we really need is for the bullet to head for for the red aiming dot. Some missiles do this already, and I remember reading something on developing this for autocannon bullets (for airplane on airplane action) a few years ago.
The only down-side is that is wouldn't work against reflective armour or the Anti movie sniper helmet.
Loris, Aug 23 2011


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle