A bit of research and some helpful members explained the science to me. The image of the target may not be dead centre if the lenses are not perfectly ground or installed. The scope can be adjusted so that the point of impact coincides with the image and all is well. Scopes such as this have Parallax adjustment which basically means you are able to adjust the scope using the twist dial in this case on the lens to factor it out of the equation and get a vastly improved range of focus. Nikko Stirling Mountmaster 4-16x50 AO Rifle Scope. Hunting small game with air guns or.22 rifles is becoming increasingly popular and a challenging sport. So too are the various plinking targets available today. Usually the game or target is small and the distances can vary from shot to shot. Normally a riflescope is focuses and parallax free at 100 yards. However when the game or target is at closer ranges then focusing and parallax correction is necessary to avoid inaccuracy. The Mountmaster AO series has been developed to provide a fast correction to focus and parallax through the adjustable objective (AO) lenses. Now you can adjust right down to targets that are only 10 yards if required! This Nikko Stirling Mountmaster riflescope is ideal for shooting small game with airguns or .22 rifles. This series features a very strong 3/8" dovetail mount ring. Additionally, the new recoil stop screw allows the mount to be secured to powerful airguns without having the fear of shifting under the sharp recoil of the spring release.

Parallax adjustable from 15 yards to infinity gives you much easier and faster focus at a variety of ranges. It was an upgrade to the 4 x 32 Nikko Stirling Silver Crown that I had used for many years but unfortunately I discovered that rotating the objective bell to adjust the focus caused a large shift in the point of impact. These items normally require Identification (Passport) or a Firearms / Shotgun Certificate before they are handed over. Shotguns, Rifles, Airguns and Moderators are usually good examples. When purchasing a 'collection only' item you are in effect paying a deposit for your goods. In all instances you can choose to collect your item from one of our stores (Exeter, Dorset or Newport) or from a 3rd party gun dealer. The latter may be at an additional cost to yourself. I notice that you have now found an example of the scope that I used initially. It will be very satisfactory for 20 yard range work. The AO IR series feature a very strong 3/8-inch dovetail mount ring. Additionally we have added a recoil stop screw that allows the mount to be secured to powerful airguns without fear of shifting under the sharp recoil of the spring release.

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The AO series feature a very strong 3/8-inch dovetail mount ring. Additionally we have added a recoil stop screw that allows the mount to be secured to powerful airguns without fear of shifting under the sharp recoil of the spring release. If for some reason parcels are required to be redirected then an additional charge might be levied (where applicable). Also if goods are refused or not called for a charge might also be incurred. This list is not a full and exhaustive list and other reasons may apply.

The effect varies in intensity and effect at different ranges so the scope features a range of adjustment settings. Parallax yard settings from 15 yards a djusted by the objective i.e., it is an AO "Adjustable Objective" scope.

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Whilst I'm sure that Nikko Stirling now use a similar design I have never bought another of their products. If you intend shooting most of the time in low light conditions ie dawn and dusk then the larger lens may get you an extra half hour of shooting time. However, better quality glass will more than compensate for the larger lens diameter and it won't compromise your depth of field like a larger objective, that requires you to adjust the AO every time you alter your range by a few feet.