Zeroing a rifle scope.
This is something that you more or less have to do yourself. I have often seen folks on my range zeroing rifles for others before a limit and there are usually a lot of bleats during the hunt. Zero your own rifle!
You will do a lot of this work from the bench, but make sure you print a couple of targets afterward freestyle, with shooting sticks, or however you will actually be using the gun.
It should go without saying, but zero the rifle with ammunition similar to what you will be using in the field. If you are shooting a .308, and will be carrying 180gr soft nose bullets, don't do your initial zero with lighter 7.62mm ball rounds. Once you have the scope zeroed, you can make all sorts of adjustments for different ammo and loads.
And lastly, you can only zero a rifle if the scope has been properly mounted. This is also not rocket science--for some, with the proper equipment and a little skill--but for most people, it's probably best left to a competent gunsmith.
There are a number of "zeroing targets" on the market, and you can download just about any kind of target you want off the excellent Firearms Guide DVDs, but you can also use a paper plate or other material and make your own target--just keep it simple. You need a central aiming point that is not too big, but easily seen from the distance(s) you will be shooting from. I normally use a black patch off a roll in my range bag, which will be around 3/4" in diameter, t place this in the centre of my blank card, and then draw a horizontal line through the patch to both edges of the paper and a similar vertical line so that the patch forms the centre of a cross.
When I plan on doing my zeroing, I make sure I have plenty of rounds made up, and I try to do it on a day with good ambient light and little or no wind. I will probably be chronographing too, if I'm using my own loads or have changed any components, so I will want to record the group size after zeroing as part of the data in my file. I have used the data sheets supplied with my Chrony--though I confess these days to working off of a CED--and they contain all the information I will ever need to reference back to.
The following guide is how I do it:
1. If it's a new scope, I will set my zeroing target at 20m, and even if my scope is zeroed I will put my first rounds downrange at a close target.
2. My range hosts a lot of bench-rest competitions, so there is no shortage of suitable concrete benches, which will give me all the support I need. I spend a little time setting my rifle up on the sandbags--I haven't bought a fancy bench-rest rifle rest yet--and I take a little time laying out everything where I can access it without having to move around too much. I also set up my spotting scope on a tripod, because I will be moving the target farther out. Bench-resting heavy rifles isn't a lot of fun, but then again. I'm one of those who believes that most of them shouldn't be scoped anyway.
3. If I'm confirming the zero on a tried and true rifle and scope combination, I put three rounds onto the target and I should be able to cover them all with one patch. I also always fire a fouling shot off-target first (yes, I know that the fouling shot is the really important one, but ...). If it is a new rifle/ scope combination, then I may fire a couple of three-round groups to establish my starting point. I am never in a hurry when I'm doing this.
4. If I'm not looking at more or less the same blank target I started out with after firing the first rounds, I know I have to adjust windage and/or elevation. At this distance I should be able to start correcting with very small increments--a couple of clicks of the adjustment knob at a time, depending on how far out of true the first group was. Make sure to adjust in the correct direction--some scopes differ in their calibration. The top dial should control elevation and the side dial windage.
5. I make a minor adjustment, and then fire another three rounds. If my group--and it must always be a group--is coming closer to centre, I keep repeating this process until my group is where I want it to be. My main reason for making small adjustments is that I don't want to "over-shoot" the mark and have to start coming back again in either plane.
6. The bullet's journey will follow a parabolic curve, along which it is affected by air resistance and gravity, both of which decrease its velocity. Assuming that the bore and the target are horizontal along an imaginary base line (the muzzle will be elevated) the bullet will pass through its mid-range trajectory, which is its high point in terms of elevation above the base line, and continue to descend until it hits the ground.
Where it again crosses the base line on its way down is where you are zeroing for.
7. If you are shooting a "typical" load, and you have zeroed your scope for 20-25m, you should be pretty much spot-on at 100m. Move your target out to 100m and check the zero, again taking your time. You should have to adjust minimally if at all.
8. This is basically where I go home happy, or repair to the clubhouse for the amber nectar. If I were going to someplace like Namibia, I would possibly want to re-zero for 150m or 200m, which is basically a repeat of the above steps, but these days if I have to take a shot at something farther away the 100m, I'm probably out of my weight class.
9. If I am going to shoot metallic silhouettes at known ranges, I will even write down how many clicks adjustment I make for the various distances, but of course I will re-check my zero every time I plan on using the rifle or change any of my loads or components.
If this sounds tedious, well, it's tune spent shooting on the range, so it can't be all bad, right? Enjoy!
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|Title Annotation:||Tools of the Hunt: The hunters and their equipment|
|Publication:||African Hunter Magazine|
|Date:||Jun 1, 2016|
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