When mounting a scope on a gun, it's a good idea to “boresight” it, or align the crosshairs (iron sights) with the barrel, before attempting to zero it in. This will save time and ammo. A simple method which can be used on, centre/rim fire rifles or airguns which allows one to look down into the barrel. There are many devices in the market to do just that on any rifles etc. This method was taught in the Army and no special device or tools are required.
Safety First.
• Check if the gun is loaded; if so, unload it.
• Always keep guns pointed in a safe direction.
• Remove the bolt.
Remove scope capes etc and have a small coin or similar to turn the scope screws handy. If iron sights then the tool to loosen the sights.
1. Select a safe area and an object 100 M away for the rifle to be pointed at a safe distance. The object can be a target card or anything that stands out.( The distance where one selects an object can be less then 100m for air rifles.)
2. Place the rifle in a steady rifle rest, etc. Can be anything, the idea is to firmly rest rifle on. (must be able to raise or lower the rifle rest)
3. Remove the bolt from the rifle. Here the idea is to be able to see down the barrel from the breech end to bore sight your rifle.
4. Look through the barrel of the rifle from the breech end and move the rifle rest etc until the object at 100M is in the centre while looking down the barrel. (looking in the barrel at the object.) you may have to raise or lower the rifle by adding a book or two under the rest until you have a near as perfect picture of the object while looking down the barrel.
5. Without moving the rifle, adjust your scope (iron sights) so that the crosshair is aligned on the object. Your rifle is now bore sighted at 100M.
6. Tighten screws and replace scope screw caps.
However this does not mean that your rifle is zeroed in for 100 M, Now you have to go to the range and zero it in. By bore sighting you should be able to hit somewhere on the paper target.
Rough Guide to Zeroing http://indiansforguns.com/viewtopic.php ... 695#p40695