The new Absolute Zero sighting device from Axeon Optic Solutions, a subsidiary of Umarex, promises fast sight-in with as few as three shots. It's a clever device that saves time, and it also saves money in the way of using less ammunition to get the job of sighting-in done. Here's how it works.
First, install the two CR2 batteries. Attach the Absolute Zero to the riflescope by installing the mount ring with the four provided screws. As is, the mount ring fits a 30mm scope tube; a supplied plastic spacing ring can be used to fit the mount ring to a 1-inch scope tube. Use the built-in rail mount on the mount ring to attach the Absolute Zero device. Be sure the Absolute Zero's lasers are pointed the same direction as the rifle's muzzle and that the unit is vertically aligned. Place the included reflective chart on a target at 25 yards so it can be seen through the scope. The chart has lettered and numbered boxes. Activate the Absolute Zero by pressing the red button so that both lasers hit the reflective chart. Make a note of the lasers' locations on the reflective chart. Load a round in the rifle's chamber, hold the lasers so that they hit the same locations as before, and fire the shot. After the shot, place the lasers back on the same positions as before, maintain a proper cheekweld on the rifle, and while keeping the lasers on the positions, adjust the scope's windage and elevation dials until the reticle is centered on the bullet hole. The rifle and scope are now zeroed at 25 yards.
Now fire a round on a target placed at 100 yards, make the necessary adjustments based on the click value of your scope, and fire another round to complete zeroing your rifle and scope combo at that distance.
I have used the Absolute Zero to sight-in an AR, a 10/22, and a bolt-action rifle, and the device worked exactly as advertised.