Shooting Off A Rest
There are a lot of similarities between shooting rifles off the bench and shooting slug guns, however knowing and practicing the differences can equate to putting more meat in your freezer.
When you first arrive at the range be sure to create your shooting setup on a sturdy, fixed base such as a heavy table or bench. Position a solid rest under both the forend and butt portions of your gun's stock. It is not sufficient to rest only the forend of your gun's stock or to rest on a non-solid item such as a folded coat. Do not attempt to zero your gun from a non-fixed base like the hood of a truck.
Adjust the position of your gun as it sits in the forend and butt rests so that without having to touch the firearm the sight picture is dead on your target. Slide your body into shooting position without disturbing this sight picture. Begin applying shoulder pressure to the butt of the gun and offset any forward gun movement by pulling straight back with your right hand in trigger squeezing position. With your left hand on the forend of the gun's stock, pull firmly straight back and down at a 45-degree angle. Hold this pressure on the gun as you concentrate on keeping the cross hairs fixed dead on your target. Squeeze the trigger gently straight back until the gun fires. It is common for a shooter to anticipate the gun blast as well as the recoil, but both should come as a complete surprise when a perfect shot is made.
Consistently integrating the above procedure into your shooting sessions will eventually produce shot groupings you will be proud of. Keep in mind that 60% of your overall group size can be directly attributed to inconsistent left hand pressure. Wind is also a significant negative factor when attempting to shoot small groups. Learn to read the wind!
Slug guns must be zeroed (sighted-in) at a distance where the slug will impact the target while still in the supersonic phase of its flight. Most slugs become subsonic, traveling less than 1220 ft/sec, slightly beyond a muzzle distance of 50 yards, thus making 50 yards the ideal zeroing distance. Zeroing at 50 yards also cuts down, by approximately 60%, the chance of adjusting windage error into your scope setting.
A common shortcut taken by a majority of shooters is the attempt to zero their guns at 100 yards. When sighting in a slug gun at 100 yards you have only sighted the gun in for "the wind of the day" that was there while you were shooting!
In most cases THE SLUG GUN IS ONLY WITHIN 10 INCHES OF WHERE YOU THINK IT IS ZEROED...