Instructables

A Laser Boresighter

Using a cheap laser pointer to create a laser boresighter, which can be used to check sights on airsoft/rifle/pistol/bb gun and even a crossbow.

The two basic types with pics below are
  1. the cartridge type which is loaded via magazine into the breech.
  2. the bore type which is slid down the barrel from the muzzle end.
The easier of the two versions to make is the bore insert which Ive decided to tackle. This is the way Ive gone about it but other methods will also work.
 
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Step 1: Parts and Starting

bolt 2 threads cleaned.JPG
bolt 1 drilled threaded.JPG
laser bolt2 apart.JPG

All you really need is the laser and a mount. I used the el cheapo 1mW red pointer although the more powerful green ones will also work with suitable mounting.
Actually the green ones would be better if you were wanting to sight in longer than 20 metres as well as during daylight hours, it would be more visible than the cheap red 1mW ones.
The mount should be adjustable to compensate for the fact that most lasers aren't centered in their housings and also interface between the laser and barrel bore.

I chose a 19mm bolt as the mount and threaded  the end to accommodate different rod sizes. eg BB gun bore is 6mm and CO2 guns 4.5mm (actually 0.177 inch)

I figured I could make use of the ball that the key chain attaches to on the end of the laser, to make a swiveling sort of coupling.




Step 2: Laser Swivel

bolt 2 black.JPG
laser bore sight 2.JPG
Next add the adjustable tabs, determining how long they need to be, mine were 35mm long.
The size bolt was 19mm across the flats which seemed to afford enough space to adjust the laser body.

I also read about a treatment with steel that gives it a black color and experimented with everything steel related. I heated the bolt red hot and then dunked it in old used motor oil, gave the little metal strips the same treatment.

The tips should be pointed to make adjusting easier, works better than the flat bolt end on the rounded laser body
bluumax1 year ago
Great idea! Simple & c lean.
I was reading a post on http://www.gulfcoastfishingconnection.com/forums/forum88/thread17202.html#7 There's a good idea for Idea for centering / calibrating.

"patoz - Actually, all you need to do is chuck it up evenly in a variable speed drill, clamp the drill in a vice or anything to immobilize it in a horizontal position, and fire the laser at you neighbor's house across the street. Turn on the drill slowly and if you see one green dot, it's centered. If you see a green circle, then it's off center. If what you see looks like an old style oscilloscope screen, then it's time to buy a new drill. "

"choppedliver - thats a good idea...(smacking forehead). Should i take it out of the rifle first? "
thebear11 year ago
nice job thanks been looking for something like this
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