Target Sports

TARGET RIFLE BASICS: POSTIVELY NEGATIVE

Created on 18th May 2009

CHRIS WHITE clears up the mystery of foresight adjustment

HOW DID you get on with last month's little test? Could you read the sight setting in Figure 1? The correct answer is minus three. Because this figure is a negative value we need to read the vernier backwards. You should appreciate by now that this is quite difficult, even more so under pressure in the pouring rain. I hope this demonstrates why it is important to avoid ending up with a negative value on your sight.

We already know that it is vitally important to have the eye directly behind the rearsight (see Target Sports, April, 2007) and that to achieve this we need good and consistent contact between the cheek and the butt stock. Up-and-down foresights for NRA Target Rifle have been available since the late 1980s. They are currently available from Fultons, RPA and Paramount (and Centra) in the UK and Sinclair (an apparent copy of the Fulton design) in the US. I am prepared to stick my neck out here and say this is the single most beneficial gadget you can fit to your rifle.

These gizmos are generally adjustable in increments of five minutes; the Centra is adjustable to finer increments and pretty much guarantees good contact between cheek and stock, if used correctly.

We saw last month that the rise from 300 to 1,000yd is around 30 minutes; in old money that is 3/10"(one rifle minute is 1/100"on the rearsight). So if our head is on the stock at 300yd it will be a 1/3" off it at 1,000yd. With our up-and-down foresight, however, we can move the foresight that amount. This means that our elevation setting on the rearsight will be the same for 1,000 yards as it is for 300yd; to quote Mr Daniels, "Now that's magic!"

To fully understand this let's just re-cap. To increase elevation we need to raise the muzzle of the rifle. Raising the rearsight has this effect because as the rearsight goes up the muzzle must also go up to ensure that the foresight appears in the middle of the rearsight. Surely that is straightforward? But we want to keep our head in the same place. To achieve this we must lower the foresight; that is why Messers Fulton et al. have arranged the graduations on their foresights to increase in value as the sight moves closer to the barrel.

Now let's look at how not to zero the rifle with an up-and-down foresight. I normally avoid negativity but the following is a useful example because this is the method used by most shooters.

Step one is to set the foresight at zero, as shown in the picture above. Go onto the range at 200 or 300yd and find an elevation zero as described in last month's issue. Then, until you have more data, set your sights at six minutes up from this number at 500yd and 93/4 minutes up at 600yd.

Step two: wait until you are going to shoot at 900yd, set your foresight at 25 minutes and come down ¼ minute from your 300yd ‘zero'. You will then find your 900yd elevation and can come up 6 ¼ minutes when you go to 1,000yd.

As Oliver Twist found out something is better than nothing and this seems to work well for a lot of shooters. It does no more than can be achieved by having two foresights, a ‘high' one for short range and a ‘low' one for long range and it does not take advantage of those five minute (or better) adjustments that the manufacturer has built into the foresight.

This series is entitled Target Rifle Basics but the following is so fundamental to good shooting that I am going to cover it here. You will need a rifle that is already zeroed or have access to a friend's rifle, which is zeroed. Remove your up-and-down foresight from the rifle and assume your position. Get your friend to raise your rearsight until it comes directly in line with your eye. Get up and down again to check this until you are confident that the rearsight is in the optimum position for your shooting eye when you are in a relaxed and comfortable position. Whatever setting is on the rearsight is the optimum and we ideally want to keep within three minutes of this setting.

Now measure the height of your friend's foresight from the bore line and also that of his rearsight. Subtract the first figure from the second and refit your foresight so that it is set lower than your rearsight as close as you can get to this value. The aim is to get the sights in the same relative position to each other as your friend's. This will maximise your chances of getting onto the target when you go to the range for your zeroing session. To minimise the amount you move your rearsight so you must move your foresight. If your group centre is more than 2½ minutes from the centre of the target move the foresight down if the shots are going low and up if they are going high.

You now have two settings to record: your foresight setting and your rearsight setting. Assuming you have zeroed at 300yd you can then raise your elevation by the six minutes required at 500yd by lowering your foresight by five minutes and raising your rearsight by one minute. Similarly, when you go from 500 to 600yd and want to increase your elevation by 3¾ minutes you move your foresight down five minutes, which raises your elevation by five minutes and lower your rearsight by 1¼ minutes to get the total raise of 3¾.

Take a look at the table, which is the elevation table for my short-range rifle (Barnard). Note that between 200 and 800yd there is no more than 1½ minutes variation either side of a mean setting of 16½ minutes.
This way your rearsight settings (and your head position) should all be within a three-minute bracket of your average setting irrespective of the distance at which you are shooting.

Next time we'll look at zeroing the windage.