Side Wheel Scopes for Field Target

The popularity of high magnification scopes with side-wheel parallax adjustment has made the job of calculating the range to target much more achievable and certainly more user-friendly. Adjustable objective lenses work fine but in the World of Field Target shooting anything that makes the job easier is a welcome addition to the shooter’s armoury.

Knowing this, a friend recently fitted a new Nikko 10-50x60 FT scope to his rifle and was disappointed to find that after calibrating and marking all the ranges, the results were inconsistent. Sometimes he would get the distance right, but next time it would be different and so on. The root of the problem was that he really didn’t use a method that would give him the consistency required for repeated and accurate range finding. Unfortunately, this is not a rare situation for novices and one can be forgiven for thinking that it’s a simple matter of winding up the magnification, turning the side wheel, and, after some twiddling back and forth to obtain a clear sight picture, reading off the marked range on the side wheel. To the casual onlooker this is exactly what they see the shooter doing, unaware that this exercise requires as much thought, skill, and practice as the actual taking of the shot.

This month we will look at some basic requirements and try to give an idea as to what scopes will do the business as far as FT shooting is concerned.
                                                         
Focus or parallax?

Manufacturers commonly use the term `focus` when describing the `parallax` adjuster on a particular scope and although most people understand the term `in focus`, they haven’t a clue what `parallax` means. Hold up your index finger at arms length and view it with your right eye closed. Now close your left eye while opening your right. The finger appears to have `jumped` position without it actually moving at all. What you are experiencing is parallax. To a lesser degree, this effect can manifest itself when viewing an object through a telescopic sight. Any side movement of the viewing eye will alter the apparent position of the cross hair in relation to the target resulting in a rifle that is impossible to zero correctly. The answer - is the Parallax adjuster!

Most low powered scopes have no parallax adjustment for two reasons: As the magnification decreases, so does the problem of parallax error. The scope will be factory set to be parallax free at a particular average range. Usually 50- 100yds for firearms, or around 30yds for airguns.

Once we enter the world of high power optics, usually deemed as X12 magnification and above, the parallax adjuster becomes the norm on telescopic sights. In theory, this is turned until a clear sight picture is obtained. At this spot, the scope should be `parallax-free` but in reality, this isn’t always the case. A fully parallax-free situation in some scopes might need a slight `tweak` of the adjuster, taking it slightly out of focus. Needless to say, although this can be the case, I have never found it to cause an accuracy problem worthy of note. For FT purposes, using the parallax adjuster as a focus and ranging tool works just fine once the technique has been mastered and in this article I will refer to this adjuster as the focus

What’s Available?

The first things we need are the right tools for the job. Virtually any scope with a magnification above x30 with a side focus adjustment knob or wheel will be capable of range finding but it also needs to be capable of focusing from around 10 yards and out to 60. There are several importers and manufacturers offering optics with these specs and they all use a 30mm tube body.

Deben
www.deben.com
Deben is the UK supplier of the `Hawke` range of riflescopes, which have a great reputation for value and decent optical quality. The Sidewinder 30 is an 8-32x56 that comes with a larger focus wheel. Although at the budget end of the FT market at £280 it can give really consistent results and comes with a decent sized side wheel as standard.

MTC
www.mtcoptics.co.uk
This manufacturer does the Viper also an 8-32 with a slightly larger x60 Objective lens. A little more expensive at £299, there are many being used on the FT circuit.

Nikko Stirling
www.nikkostirling.com
Probably one of the most common scopes in FT is the big 60 Diamond. Very successful and a top level contender, pre-owned Mk1 versions can be picked up for around the £280 mark. The Mk2 is slightly shorter and the focus wheel works the opposite way. Around £630 new with the choice of Mil-Dot or NATO reticule. They also offer the Targetmaster which ticks all the boxes in specifications and comes in at around £320 with the choice of two side-wheel sizes and either a Mil-Dot or FT reticule.

Uttings.co.uk
Uttings import the Falcon Optics range including their 8-50x60 FT model. I must admit that I don’t know much about this particular unit but the specs say that it’s worth a look. It comes with a large side wheel and a price tag around the £320 mark.

Leupold, March, Schmidt & Bender, Sightron and Night Force. Prices rise hugely after the above examples, and not necessarily with better results. Yes, optical quality should improve, and one would also expect build quality too. But we are talking about scopes costing double, and in the case of the new March x80 mag possibly ten times the cost of the so called budget brands mentioned above, at nearly £3000. All the contacts below offer scopes that work in FT, at a price. Even with one of these, range finding is no easier, and in some cases could be even trickier. Nevertheless, there are lots of shooters willing to pay extra bucks for the top quality lenses.
www.leupold.com
www.marchscopes.co.uk
www.schmidtbender.com
www.sightron.com
www.nightforceoptics.com

Wheel and Deal

All those listed either include a larger diameter side wheel as standard, or can provide one as an extra. The larger diameter widens the angle between any given points and allows for much greater accuracy when reading off a particular range. Though it should be noted that increasing the spacing can also increase any error!

The starting point is around 3 ½” diameter for a standard factory wheel and this will expand any markings reasonably well. However, a larger wheel will expand the marks even further and there are a number of custom shops that can supply them in a variety of diameters and finishes. The physical design of these scopes means that any wheel larger than about 6 inches cannot realistically be used. Apart from the sheer ungainliness and vulnerability of such a monster, it becomes difficult to attach a range pointer. Despite this problem, there are shooters out there with a scale equivalent of the London Eye fixed to their scopes! Another point is that only half of the circumference on these giant wheels is of any practical use. The other half is surplus to requirements and prone to knocks and side strains that can damage the scope mechanism.

If a wheel reaching these larger proportions must be used maybe the ‘Expander’ or ‘Shark Fin’ custom wheels are the answer. These clever designs utilise only the business part of the wheel’s circumference (see photos) and keeps the rest of it down at 3-½ inch diameter. I personally consider this to be the ultimate FT range wheel and have used one since 2008. There are various improvisations on this idea and they all work very well. For information on custom wheels, call Barry Taylor on 01977 673377 or e.mail [email protected]. Most of his custom wheels cost around £50 plus p&p. There are other designs on a similar theme made by other suppliers.

                                                           
Using a Rubber

Another consideration is the scope ‘Enhancer’, or put simply, a rubber eyecup. Not everybody’s cup of tea but certainly worth trying. It keeps unwanted light from entering the ocular lens in front and to the side of the shooters eye and allows a sharper contrasting image. Very important when ranging a target, particularly at longer distances. As with the side wheels there are several variations available. I use the Bisley version and find that a little bit of snipping in the right places with a pair of scissors can make it fit the eye and bridge of the nose like a glove.

Shading it

The last consideration is the sunshade. This can make the difference between seeing a clear target and one that is well nigh impossible to range due to lens bloom which can manifest itself when the scope is pointing towards a bright, sunlit skyline. This gives the effect of turning the sight picture a milky white, destroying any contrast and making it impossible to range a target. The sunshade can help to prevent this and also helps protect the Objective lens from raindrops and debris etc. Scopes come with a sunshade as standard or an extra depending on the manufacturer. Extra weight and length is the penalty, plus adding unwanted surface area to side winds.

Once the choice of scope, wheel and accessories has been made, the job of marking the focus adjuster can begin. It will be in yard increments from 10 out to 20 and from that range, every 2.5-yards out to 60. With practice and familiarity it is possible to range within a foot for that first twenty, then within a yard and a half out to 55, and that’s what we will be looking at next month.