After reviewing a Ruger GP100 .357 Magnum revolver (see the Handgun Information - Reviews index page), we installed a Crimson Trace Lasergrip on our test gun. The Lasergrip is a replacement black rubber grip with a red visible laser diode built-in. Once installed and zeroed (just adjust the laser spot to coincide with the revolver's iron sights at 50 feet), activating the laser projects a red dot on the target approximately where the bullet will hit.

We replaced the GP100's stock Hogue Monogrip with a Crimson Trace Lasergrip #LG-344. This square butt, black rubber grip incorporates a red laser that projects an aiming dot just under the cylinder, along the lower right side of the barrel. The grip has much more restrained finger grooves than the stock Monogrip, allowing more flexibility in shooting hand grip and a better feel.

After removing the stock grip, the two halves of the LG-344 are installed on the GP100's stub grip frame by screws in the left grip panel. There are two small screws at the top of the left grip panel, two more identical screws in the lower center of the grip and a large screw in the middle of the grip. The center screw holds checkered black plastic inserts to each side of the Lasergrip; these cover the two lower small screws in the left grip panel. Five screws may seem like a lot, particularly since Ruger only required a single screw to secure the stock grip, but at least the Lasergrip is secure. The CR123 battery that powers the laser is nestled inside the bottom of the Lasergrip, which must be removed to replace the battery.

The laser aiming point is adjustable in windage and elevation by means of tiny screws in the top and side of the laser diode housing via a supplied hex wrench. A single CR123 lithium battery provides approximately 20 hours of continuous laser life, amounting to about a year of normal service.

The laser activation button is located at the front of the grip below the trigger guard, where the middle finger of the shooting hand naturally falls. It is a momentary switch, meaning that the laser is only on when the activating button is held in. This takes little finger pressure and, essentially, the laser is on any time the revolver is gripped normally. There is also a very small master on/off switch recessed into the bottom of the grip. This master switch allows the laser to be deactivated, useful for conserving battery life when shooting in normal daylight conditions.

Crimson Trace uses the maximum laser output allowed by law, a class 3R (5mw peak, 620-670nm) visible laser diode. At night or in very dim light, the laser dot is visible for hundreds of yards. In bright daylight, the red laser dot is said to be visible at 15-25 feet.

Indoors at night with all the room lights on, we found the red dot to be very bright at the maximum distance available, approximately 50 feet. It was also easily visible indoors in daytime. Outdoors on an overcast day (we are in Western Oregon, after all), the laser dot was bright enough for aiming out to about 20 yards against a neutral (18% gray) target. Day or night, the laser beam itself is invisible, so an armed opponent to the side cannot see it to pinpoint your location in the dark.

Crimson Trace recommends zeroing the laser at 50 feet. At any distance from the muzzle to 50 feet the point of impact is within 1.25" of the point of aim (on our GP100) and the laser dot is ½" in diameter. The Lasergrip does not interfere with holstering the revolver and a special holster is not necessary to accommodate a Lasergrip equipped GP100.

Crimson Trace Lasergrips are made in the USA and come with a three year materials and workmanship warranty. The 2013 MSRP for the LG-344 is $299 direct from Crimson Trace (www.crimsontrace.com).