Best position to barrel-mount a laser

[Ira]

I just ordered a low-level (50 to 60 bucks) green laser to barrel-mount (20 gauge) under barrel. You see a bunch of conflicting reviews on how various models of these lasers hold zero, and of course, you have to take these reviews with a grain of salt:

Some guys swear this particular model holds zero after hundreds of rounds on a 12 gauge, while other guys say it won't hold zero after 5 rounds on a 22.

Is there a significant difference in barrel "shock" if I mount it all the way forward nearer the bead, or should I mount it back and as close to the magazine tube cap as possible?

[Ira]

Well, the laser came yesterday, and I mounted her. I didn't take a picture of that yet, but here's the mount I used, and where I positioned it.



Because of the contour of the mount--not a circle but flat on two sides to accommodate the sight bar--checking with a chamber laser boresighter, the windage is PERFECT. Lines up EXACTLY at about 15 yards.

And elevation is off as you would expect; have to raise the elevation.

So far, so good.

[Synchronizor]

I would be inclined to mount the laser closer to the magazine cap (while leaving enough space to remove the cap without having to take off the laser), rather than out at the muzzle, simply to keep the gun better-balanced and quicker to swing. The laser should experience about the same recoil acceleration no matter where it is along the barrel, though I suppose it might get dirtier and/or experience more intense pressure waves if it's closer to the muzzle.