HFT RANGE FINDING WITH SCOPE PARALLAX
January 8, 2013 | Author Brian Samson
August 25 2019 | Edited by Steve O'Mara
Range finding by eye can be quite accurate with practice, but wouldn’t it be nice if there was a yard wide line painted on the ground right across the midpoint of the course? Well, there is! (Although its not painted on the ground). All you need to do is learn how to look for it.
Why 23 yards?
If you set your scope up as I suggested in the HFT scope setup guide you might have wondered why I suggested setting your scope’s parallax to 23 yards.
Generally speaking if you want maximum clarity for all targets between 8 yards and 45 yards then a slightly lower parallax setting would work better – around 17/18 yards depending on your scope. But I chose 23 yards because it gives acceptable clarity for the close targets, slightly better clarity for the longer targets and also slightly less maximum parallax error on the longer targets. It also means that at around 20-25 yards you’ll get practically no parallax error. 20-25 yards is quite a common range for 15mm kill zone targets that need pinpoint accuracy. It shouldn’t come as much of a surprise that technically a 15mm kill zone target at 25 yards requires more accuracy than any other target on a Hunter Field Target course.
Range finding by eye improves with practice, but when you first start you might find it easier to estimate where the halfway point between two points is rather than estimating a range in yards. If you know where the 23 yard point is, with a little practice you can fairly accurately estimate where the midpoint is between the shooting peg and the 23 yard point.
That gives you your 12/13 yard distance – it so happens that 13 yards is the minimum distance a 15mm target can be set out according the rules.
Now you know the ranges for 12 and 23 yards, with practice you can estimate 35 yards ( 23 yards plus 12 yards ) and 45 yards ( 23 yards times two ).
So if you can find the 23 yard reference point and you’re prepared to put in some practice you can figure out 12, 23, 35 and 45 yard ranges.
Those ranges can also sometimes be corroborated by the rules for target placement. 13 yards is the minimum distance for a 15mm kill zone, 25 yards is the maximum distance for a 15mm kill zone, 35 yards is the maximum distance for unsupported standers and kneelers and of course 45 yards is the maximum target distance in HFT.
Learning to see the 23 yard reference point
Field target shooters are used to this method, it boils down to being able to tell when the sight picture and crosshair are in perfect focus.
Rather than try to explain what to look for, I’ve rigged up a camera to take photos through my Leupold VXIII scope with Gen2 Mildots. It’s not possible to capture a photo of exactly what you’ll see through a scope but I’ve done my best. You’ll find that the photos aren’t quite as clear as you’ll be able to see with your own eye but hopefully they’re good enough to be able to illustrate what I’m talking about.
The devil’s in the fine detail
Not only the devil, but also the secret to rangefinding by parallax. This is something that’s very familiar to Field Target shooters but may be new to Hunter Field Target shooters.
Take a moment to study this photograph.
The crosshairs are trained on a clump of leaves at exactly 23 yards and if you look closely you should be able to see all the fine detail and vanes of the leaves.
Now look at the grass above and below the crosshairs (about half way up the thick post of the crosshairs). The grass still looks fairly clear but it’s not as easy to make out individual blades of grass as it is when looking closer to the centre of the sight picture. The grass is more blurred the further you look away from the centre of the sight picture.
The total distance between the bottom of the sight picture and the top of the sight picture in that photo is only a couple of yards in total and you should be able to see that only about half a yard at the centre of the picture is in crisp clear focus. When you’re looking through a scope with your eyes rather than a camera lens the area in focus is larger, but you should still be able to see about a yard of sight picture that’s in crisp focus.
The more fine detail you can find, the easier it is to see when something is in sharp focus or not. Reliable things to look for are things like tree bark, grass, leaves, screw heads, the frayed end of a reset chord etc.
The more practice to have at this the more accurate you’ll be to the point where being able to accurately range find 23 yards by one quick glance through your scope is going to be a doddle.
To give you some more obvious examples, here are 3 photos of a target at 23 yards, 18 yards and 28 yards. Look for details on the target faceplate such as the screw heads and the detail of the edges of previous pellet strikes that have been sprayed over.
Telling the difference between 40 and 45 yards at a glance.
There is another focus trick you might be able to use to be able to tell the difference between a 40 yard and a full distance 45 yard target. This method isn’t as reliable as the 23 yard method and will be dependant on your scope, your eyes and the lighting conditions.
It’s fairly simple, and just involves learning to tell the difference in the amount of blur between a target at 40 yards and a target at 45 yards.
On some scopes with the parallax set at around 23 yards the difference in blur between a full distance target and a 40 yard target can be quite noticeable.
Personally I find this method to be too unreliable, but it’s worth checking to see if it’s a method you could potentially use.
How to use the 23 yard method on a course.
You’ll need to find your own method of doing this when shooting a course, and it’s going to depend on the lane you’re shooting. Firstly, have a rough guess at where you think 23 yards is going to be and have a look to see if there are any objects with enough fine detail to be able to see your focus point. If you’re on a lane where there are lots of trees then you can do this while you’re prone at the peg, if the lane is in open ground with just grass between you and the target you might need to put the scope to your eye before you get down into the prone position. Range estimation by eye is best done while you’re standing up and this technique will involve some estimation by eye ( to double and halve distances ).
You might not want to incorporate this technique for every lane, and indeed it might not be possible to do in some lanes, so choose when to do this carefully and try to use the information on subsequent lanes. For example, if you use this technique on a lane and you identify a feature that’s at exactly 23 yards, look over to the next lane to see if you might be able to use that feature as a reference point for the next lane.