A Case for Mounting Lasers Above the Bore Line
Oleg Volk 12.02.14
Traditionally, lasers have been mounted under the forend of long guns. Mounting them on the side added yet another offset from the bore, and mounting on top usually didn’t work because the front sight would occlude them. However, the top is the best place for a laser if your firearm allows such mounting, especially if it has a straight stock configuration and there’s no front sight to occlude the beam emitter.
Lasers are mainly short range aiming devices. Up close, sight offset from the bore can be a problem, and a small laser can fit much closer to the barrel than a sight that has to provide for a comfortable cheek weld.
Typical sight offset for an AR15 is 2.5 inches. That leads to such close/far zero combinations for iron sights as 25/300 yards. A laser that sits 1.5″ from the bore can have 50/150 yard zero, with bullet being no more than 1.5 inches from the laser spot from the muzzle to 185 yards, while irons would be sighted nearly 9.5 inches below the point of impact!
More importantly, mounting the laser below the bore only gives one zero instead of two. If zeroed for 25 yards, the laser dot would be very substantially higher than point of impact at longer ranges, 9 inches low at 100 yards, for example. More importantly, it eliminates the confusion in the mind of a shooter used to estimating hold-under and hold-over with top mounted iron sights and optics. Aiming low close up and high at longer range with a laser mounted under the barrel is counter-intuitive for most people.
Other reasons for mounting light/laser combinations above the bore is that they are less likely to be obstructed by support or cover, and the partial occlusion of the flashlight beam by the barrel would cast the shadow down rather than up. Since guns are typically pointed down when held at the ready, the shadow would be on the ground and not on the suspect whose hands or face you may be trying to see.
Top mounted lasers are possible even on guns with fixed front sights. The laser goes in front of the sight tower, and activation is by a tape switch. Another option is using offset backup iron sights, which are generally preferred for rifles with magnified optics anyway.
