Holosun IRIS-GR3

Install the CR123A and Confirm Power

1. 01

   Clear the firearm

   Remove all ammunition and magazines, verify an empty chamber, and confirm the firearm is unloaded. Holosun puts this first in the manual's warning list, ahead of any battery or mounting work.

2. 02

   Unscrew the battery cap counter-clockwise

   Turn the cap CCW until it comes free, then remove and properly discard the used cell.

3. 03

   Inspect the compartment and the O-ring

   Check the battery compartment for dirt, moisture, or corrosion and clean it if needed. Inspect the O-ring seal on the cap for sand and dirt particles and for damage. A compromised O-ring is what costs you the IPX8 rating.

4. 04

   Install the cell in the marked orientation

   Seat the CR123A in the orientation marked on the housing, then thread the battery cap back on in a CW direction.

5. 05

   Verify power before you trust it

   Rotate the power selector to L, set the mode selector to VIS, and press the activation button. The green laser should light. A steady red indicator LED instead means the cell is under 2.3 V DC.

Mount the IRIS-GR3 to a Picatinny Rail

1. 01

   Loosen the clamp screw

   Use the included T10 Torx tool to loosen the clamp screw by rotating counter-clockwise. Back it off only far enough to open the clamp.

2. 02

   Open the clamp block onto the rail

   Adjust the clamp block enough to attach the mount to a Picatinny rail. Pick a slot that puts the activation button under your support hand without forcing you to break your grip.

3. 03

   Torque the clamp screw to 30 in-lb

   Apply forward pressure to the IRIS and tighten the mounting clamp screw to 30 inch-pounds. Use an inch-pound driver or a torque limiter; hand feel on a short T10 overshoots this value easily.

4. 04

   Check the clamp before you leave the bench

   Pull the unit fore and aft. Any movement means the clamp block is not seated in the rail slot. Loosen, reseat with forward pressure, and retorque.

Read the Two-Selector Mode and Power Layout

1. 01

   OFF, L, and H on the power selector

   OFF powers down the unit. L is the low power setting for the visible laser, the infrared laser, and the illuminator; H is the high setting for all three. On the GR3 the visible laser runs under 1 mW on low and under 5 mW on high, and the IR laser runs under 0.4 mW and under 0.7 mW.

2. 02

   VIS, the visible laser pointer

   Drives the 520 nm green pointer only. This is the daylight zeroing mode and the only output you can see without a night vision device.

3. 03

   IR, the infrared laser pointer

   Drives the 850 nm infrared pointer only, at 0.5 mrad divergence. A clean aiming dot under night vision with no flood signature.

4. 04

   IL, the infrared illuminator

   Drives the 850 nm VCSEL illuminator only, rated under 10 mW on low and under 60 mW on high. This is the mode you search and identify with, not the one you aim with.

5. 05

   DI, dual IR pointer plus illuminator

   Runs the infrared pointer and the illuminator together. This is the standard engagement mode under night vision because it gives you the aiming dot and the lit scene at the same time.

Activate the Laser and Set the Auto-Off Timer

1. 01

   Set power, then mode

   Rotate the power selector to H or L, then rotate the mode selector to VIS, IR, IL, or DI. Nothing fires until both are set.

2. 02

   Momentary on

   Press and hold the activation button. The selected emitter stays lit until you release it, to a maximum of 60 seconds. Past 60 seconds the laser turns off while the button is still pressed.

3. 03

   Constant on

   Double press the activation button. The emitter runs continuously for up to five minutes and then shuts off automatically. A single short press powers it off early.

4. 04

   Program the auto-off timer

   Dial the power selector to OFF and hold the activation button for five seconds. One flash of the visible laser means the five-minute auto-off is active. Three flashes mean it is deactivated.

Zero the Co-Aligned Lasers

1. 01

   Stage the target and do the click math

   Set a paper target at your chosen zero distance and shoot from a stable rest. At 0.5 MOA per click that is roughly 8 clicks per inch at 25 yards and 4 clicks per inch at 50 yards.

2. 02

   Select VIS on high power

   Set the power selector to H and the mode selector to VIS. High power puts the green dot at under 5 mW, which is the easiest output to spot on paper in daylight.

3. 03

   Fire a three-round group

   Hold the green dot on your aiming point and fire three rounds. Measure the group center against the dot's position, not against your irons or optic.

4. 04

   Adjust elevation on the top turret

   Insert the flat-tipped end of the included tool into the top turret slot, marked U. Clockwise moves point of impact up and counter-clockwise moves it down.

5. 05

   Adjust windage on the right-side turret

   Move to the turret on the right side of the housing, marked R. Clockwise moves point of impact left and counter-clockwise moves it right.

6. 06

   Confirm, then verify the IR pointer under night vision

   Fire a confirming group with the visible laser. Then switch the mode selector to IR and check under a night vision device that the infrared dot falls on the same hold. Co-alignment is set at the factory, but confirming it is the only way to know a hard impact has not shifted it.

Tune the IR Illuminator Spot Size

Install and Use the Crane Remote Cable Switch

1. 01

   Plug the switch into the remote port

   Remove the rubber cover from the remote port and insert the plug of the remote cable switch into the port until it seats.

2. 02

   Loosen the clamp screws

   Use the included T10 Torx tool to back the remote switch clamp screws out counter-clockwise, far enough to fit the pad over a Picatinny rail.

3. 03

   Clamp the pad where your hand already rests

   Apply forward pressure to the remote cable switch and tighten the clamp screws just enough to prohibit movement without over-tightening. These are small screws in a pressure pad, not a rail mount.

4. 04

   Test both buttons against the selectors

   Rectangular button: should behave exactly like the on-body activation button, momentary on a hold and constant on with a double press. Circular button: should fire the low-power visible laser even with the power selector dialed to OFF.

Clean and Store the IRIS-GR3