Most helpful critical review
131 of 136 people found the following review helpful
Unlike the other Sightmark boresights - has a wire and battery box and keeps the bolt slightly open
on October 4, 2011
I've uploaded some photos to let you see what this 22LR boresight looks like and how it works, since the Amazon photo does not clearly show the 22LR boresight.
Basically, unlike the other Sightmark boresights, the 22LR "bullet" that goes into the gun's breech contains only the laser, as the 22LR form factor is too small to hold any batteries. A one foot long wire connects the 22LR Sightmark "bullet" with a battery box outside of the gun. The box holds two AAA batteries and has an on-off switch.
The AAA batteries are cheaper and longer lasting and save you the trouble of getting extra silver oxide button batteries, used by the other Sightmarks. However, the design raises several other issues, especially with 22LR pistols that use a slide action.
The laser "bullet" is longer than a 22LR round. This extra length keeps the bolt from closing the chamber and shearing off the wire. Still, the wire looks delicate and flimsy and there is a potential durability issue here of the wire eventually breaking after extensive use.
The Sightmark boresight works fine for non-slide action pistols such as the Ruger 22LR pistols. It would work fine for 22LR rifles also.
In 22LR pistols with a slide action (e.g., the Walther P22), the iron sights, slide action, and bolt are all mechanically linked together and move together. Some slide action pistols also have a barrel that tilts in a movement linked with the position of the bolt and slide (the P22 barrel doesn't tilt).
Since the 22LR Sightmark boresight does not allow the bolt to close completely (see uploaded photo), there is the potential for the laser boresight to not be pointing in the final alignment of the iron sights and slide-barrel combination when the slide is fully closed in these pistols.
Still, the potential for mis-alignment would be mostly in the up-down direction. Using the 22LR Sightmark boresight in my P22, I found that the sights were aimed slightly to the left of the laser dot. The P22 fortunately has an adjustable rear sight (or maybe this was why it was mis-aligned in the first place).
And so because this 22LR Sitemark boresight keeps the bolt from closing completely, its accuracy for slide action pistols is a bit uncertain. It will work fine for all other guns where the position of the bolt is not linked to the rest of the gun's frame, barrel, or sighting mechanism.