How to fit a Zero a Scope or General Sights
Copyright T. R. Robb 2000
How to Fit & Zero a Telescopic Sight or what we have shortened to Scope.
To adjust the scope don’t forget to remove the dust caps that cover the adjusting knobs. We do not show removing these in the video.
No one else can fit and zero the Scope exactly right for you. Only you can set it up for you. Any one else is just guessing. Try to set the scope with the correct eye relief. This is usually two to three inches from your eye.
Looking through a rifled Barrel.
To check for the correct eye relief with an unloaded gun, hold the gun up with your eyes shut, in front of a mirror. Then when you open your eyes it should be set for you without you moving your head back or forwards.
IF YOU HAVE THE SCOPE SET TOO CLOSE TO YOUR EYE, A RECOILING GUN CAN CUT YOUR EYEBROW OPEN. This is generally called a snipers eye.
Mount the scope to give the recommended eye relief, this is usually about 2 - 3 inches from you're eye. if you the eye relief too close, it is possible that a gun with heavy recoil can give you a snipers eye. That is a big cut over and around the eyebrow. With the correct eye relief it is more sturdy to have the mounts as far apart as possible. The scope must be secure.
If you ever have accuracy problems with a silencer fitted, it is a simple test to try again without the silencer. If the point of impact moved or the group is better then have the silencer bored out a little more to clear the pellet/bullet.
This can be a common problem with silencers that are fitted to an adaptor that slide over the barrel. This is made worse with the type that has a small grub screw to lock it on, as this will tend to take up the slack on one side only. Pulling it more off centre. This is compounded by barrels not having the bore central to the outside diameter. See the gun article page about ACCURACY PROBLEMS on this web site. just click on it above.
If you have a problem with running out of adjustment, then you can put a small shim or card under the scope tube. If the point of impact is low and you have the maximum adjustment up then you can put a small piece of card under the rear of the scope tube. If it is too high then the packing should go under the front tube. Just remove the top mounts and raise the scope tube off and then place the card under the tube and then re tighten.
To make the most of your airgun you will need to know the gun outfit extremely well. The easiest way is to practice, but also there are a few things that you can do to really get to know your gun.
I find the best way is spend a day or more zeroing your gun. When you are confident with the settings and accuracy, then you can do a range check. This just means getting to know the range and trajectory of the gun.
If you have a full power air rifle then the maximum range is about 40 yards if you, the ammunition and the gun are capable of hitting a 50 pence piece at that range virtually every time. if you can do this at even fifty yards then there should still be enough energy for humane dispatch of small vermin at that range if you are very confident. Remember it is cruel to hope for pot luck, animals cannot go to the hospital if wounded and could face a slow painful death if wounded.
To find the ranges of the gun, let us assume that you have zeroed the gun at 25 yards. If you put a target up at 25 yards then you should then be able to hit within the 50 pence bull.
Now put a target up at 30 yards and do another five shot group (again still aiming at the centre). Write the range on each target. Do this at all ranges from 10 to 50 yards. Mark these on a graph and then join the dots smoothly to get an accurate graph of that set up. You will then know how much the pellet drops at further ranges and how low it shoots at the closer ranges.
If you use different pellets then you will need to do the same test with all the types of pellet that you are going to use.
How to adjust Open Sights
If you have open sights the adjustment is not as precise, (unless you have an aperture sight).
If the point of impact is to the right then you would adjust the rear sight in the opposite direction. That is if the pellets are going to the right then you would move the rear sight to the left. And if it was shooting low then you would move the rear sight up.
If your rear sight is not adjustable with a screw or wheel then you would have to move it some other way, like if it is in a dove tail then you could tap it over to the left if it is shooting right.
Weaver mounts will generally fit Picatinny Rails but Picatinny will not fit Weaver.
If you are adjusting the front sight then you would move it in the direction the pellet is grouping. So if the pellets are grouping right then you would move the front sight to the right.