Do not tighten your scope all the way down. You must ensure that your eye relief is set up properly. To do this, simply choose the magnification level anticipate using most. On a 3-9X scope, I'd say 4 X is about right. On long range or varmint rigs with high power scopes, like 6-24X or others, I'd use the highest magnification settings. The higher the magnification, typically the more critical your eye relief is - that is if your eye is just a fraction too close or too far, then you won't see through the scope clearly and get a black "ring" in your field of view from the scope. So the best way I've found to set up your eye relief is to pick the rifle up out of the vice, close your eyes, mount the rifle, then open your eyes. If the scope doesn't appear "clear" and you can't see the whole field of view, then you must adjust the scope forward or backwards. The reason I suggest you do it this way is because if you mount the rifle with your eyes open then you'll instinctively adjust yourself to the scope, automatically moving your eye closer or further away to get the clearest view. On a quick shot opportunity, this slight pause may cost you! So, it's best to do it the way I've suggested. Now once the scope is setup for your proper eye relief, carefully place it back in the vice.
Next you must make sure that the scope is level. Though some guys will just "eyeball it" I prefer something a little more consistent and accurate. There's several tools on the market which will level your crosshairs such as the Reticle Leveler (optional) offered by several sporting goods stores (SEE PICTURE BELOW).
The way this works is to pull one of the plastic sides out of the metal cross bar. Then place the metal crossbar on the receiver of the rifle, making sure it is perfectly level (using the built-in level or one of your own) and hold it in place with rubber bands. The rubber bands are attached to one hook, pulled underneath the firearm and then hooked on the other side. Once the leveler is level, twist your scope so the crosshairs match the black bars on the face of the leveler. Then you're done!
Another option, for those who don't want to invest in one of these reticle levelers is to tack a string to the ceiling with enough string to hang beneath the firearm as it rests on your work bench. Attach a weight and you have a perfect plum to gauge your verticle crosshair with (optional). Again, just twist your scope till the crosshairs match the plum and you're set! You may need to choose a lower power setting in order to see the crosshairs clearly using this method or you can adjust the distance of the "plum" from your scope - either way will ensure your scope's crosshairs are leveled.
Once you have your scope set up for the proper eye relief and the crosshairs are level you're ready to boresight!
Boresighting is a technique used to get the projectile's path and the scope's point of aim together. Boresighting your scope simply "gets you on paper" NOT "dead on target!" If you have a bolt action firearm you need no special tools. For all other actions, you will need a laser boresighter, a commercially available periscope, or a set of anchors and a sighting tool for boresighting. Instructions for these tools will be included at the time of purchase so I won't discuss them here. However, it is important for those who will be using these tools to ensure that their scope's range of adjustment is centered as well so don't leave just yet! Go out to the range and take a target (round bullseye is my favorite to use) and set it up at 25 yards. Pull the bolt out of your firearm (or use the commercially available periscope I mentioned) and center the bullseye in the center of the bore. It's a little tricky but not difficult to get the right sight picture. The pictures below gives you the ideal sight picture as well as the common poor sight picture shooters tend to get.
Good boresight sight picture Poor boresight sight picture |
