What is your zero point?
Your zero point is the setting of your sights so you know the shot should be dead centre of the aiming mark for whichever distance you are shooting.
Why do I need to Know It?
Quite simply - it allows you to get on the with task of shooting a competition so much quicker! This, in turn, gives you more time to shoot the competition itself.
Due to different conditions you will find that your zero point varies from range to range. So even if you only shoot indoors you may find you have to adjust your sights when you travel to a shoulder to shoulder competition or a final being held at another range. Knowing your zero point will allow you to return your sights to the settings for your home range without having to waste time and ammunition sighting them back in when you return home.
The image above is of a competitor's card which was submitted for scoring during one of our open shoots. You can clearly see the timing, and the thinking, behind each shot as follows:
- Too High!
- Bit Lower!
- No - Lower Still!
- Bit more!
- Too Far - Up a Bit!
- OK - You're running out of time!
While six shots on a sighter diagram at 50m is by no means excessive, they are usually used to get an understanding of the weather conditions. Here the competitor is six shots in and has only just started that part of the shoot.
So, take the opportunity to zero your rifle at 50m and 100yd. Then it is simply a case of putting on (or off) the relevant number of clicks and you avoid the time and energy spent getting the shots in the middle and can concentrate on the range conditions and your technique.
Directly related to this is the question: "how far does the fall of shot move for each click of my sights?"
While there are some sweeping generalisations that can be made, the answer is that it depends entirely on your individual setup.
Starting at your short range (15/20/25yd) put up a card. Starting on the first aiming mark do the following:
- Put up enough shots so that you know where your group is centred.
- Put 20 clicks on you sights to move the fall of shot upwards.
- Repeat step 1 on the same aiming mark but this time the group centre will be offset from the previous group.
- At the end of the detail, retrieve your card and measure the distance between the centres of the two groups.
- Divide that measurement by 20 and you have your answer.
Tip: What I find useful is to then work out how many clicks I need to get across a ring on the target. This is useful as the targets are proportional to the distance so the answer is the same on a 100yd target as it is on a 50m target as it is on a 25yd target.
For me, the answer is about 3 clicks per ring. 6 to get all the way across the bull. Looking at the target again, the first shot (near the number 113) is so far out we've run out of rings. In this case you just have to estimate as follows:
9 rings = 27 clicks
Half the bull = 3 clicks.
subtotal = 30 clicks
the first shot appears to be roughly the same distance from the first ring as the edge of the black is from the centre. That's about 7 rings = 21 clicks.
Total = 51 clicks
Put 51 clicks on the elevation. Make sure you wind the sights the right way!
WIndage follows the same logic. Again you have to estimate but it looks about 2 rings left of centre. So put 6 clicks on the windage.
put up enough shots to confirm where your group centre is. As this was such a big move you will probably have to make a final adjustment using an unused sighter aiming mark.
The above assumes you have no cant on the rifle. If you do, you'll have to adjust the above to allow for the amount of cant you use. I have quite a bit of cant and for every 10 clicks of elevation I include 2 clicks of windage. The direction the windage is applied is obviously dependant on the direction of the elevation change.
Back to the Zero Point.
Based on the above the second shot would be very close to the centre of the aiming mark. Saving about 6 shots and the time taken to fire them!
Starting at your short range put up a clean card and as many shots as you need to confirm you are centred on the diagram. If you have to move between diagrams make sure you get your NPA reset correctly after each move.
Having zeroed your rifle make a note of the sight settings for elevation and windage.
If you're lucky you will have a set of sights where you can set the indicator to zero on both the elevation and windage directions which makes life a little easier. Especially if you've lost track of the minor changes you make during a competition. You can rewind back to an approimate zero then check the reading on the sites which will be fractionally off the zero. Then make a final adjustment back to zero.
Now repeat the above on a 50m card. Ensure you make a note of every click of the sights and the direction!
At the end you should have established your zero point for 50m. In my case it's 10 clicks on elevation and 2 clicks windage to correct the drift of the shot caused by cant. Now you can move from the indoor range to the 50m range and start shooting knowing that you should be in the middle.
Returning to the indoor range you just reverse this setting, including any additonal adjustments you have made for the weather.
Repeat the above process for a third time and you have a figure for you 100yd zero point. This can either be recorded as the change from indoor to 100yd or the change from 50m to 100yd. If you need to change from 50m to 100yd ranges you can do some simple maths to get the answer. For me, the change from 50m to 100yd is 50 clicks on elevation and 10 clicks on windage.
My figures seem a bit too perfect and I didn't believe them when I first did it. I have tried to use 51 and 9 but I keep coming back to 50/10! You may find that your initial settings need to be updated once you have some experience of just winding the changes on rather than gently creeping across the target like we started.
This process may require quite a bit of shooting so you may want to do indoor and 50m zero point on one occasion and come back to do the 100yd zero point for a second session.
Head Club Coach