sight, rifleWhat are the steps/procedures for sighting in a rifle?
So. You got a new rifle. You take it out day one and you can’t even FIND where you’re shooting. It certainly isn’t the target. How many squirrels must die before you learn how to aim it at the proper place? That’s ok, squirrels are tasty.
Zeroing a rifle is when you center the rifle’s point of aim exactly on the either the crosshairs of the scope or your center of the point of aim on your sights. Basically, if you pull the trigger, does the bullet land exactly where your crosshairs were pointing? If not, your gun is NOT zeroed!
So how do I zero my rifle?
So, you shoot your rifle at a target. You have NO idea where it landed. What do you do?
First. Bore sight. When you shoot your rifle in an open field at a target you will see NOTHING unless you got it on the target. What if you never got it on the target? Not your fault, but guns are NOT accurate right out of the box. The bullet will land wherever the barrel or BORE is pointing, not counting trajectory. The problem is how do you know where your BORE is pointing? Your scope is supposed to tell you that. It first needs to be calibrated. That is what ‘zero’ing your rifle really is. It’s calibrating your scope to your rifle. Now, in our scenario we are shooting in an open field against a target that has the sky as a backdrop. You cannot see where your bullets are landing because they’re not on target. Therefore, you have no way of knowing if your bullets are too high, low, left, or right.
What if you could look down the bore of your rifle AND look through the scope at the same time. That would make it SUPER easy to see if they lined up. Too bad our eyes aren’t on stalks. We have the next best thing. We can make the bore TELL us where it’s pointing. This is the bore sight. This is accomplished by virtually any gun dealer in the country. It can also be done by you in your own home if you have a bore sight yourself. They’re fairly cheap and can run as low as $20 at any place like Sportsman’s Warehouse. A bore sight is inserted either into the chamber (if the bore sight is shaped like a round) or into the end of the muzzle. It’s a laser. It does nothing but point straight ahead. Once that’s in there, turn it on and then adjust your windage and elevation until that laser is pointing right on your crosshairs. Bore sight done!
Your scope is NOT accurate and is NOT calibrated aka NOT zeroed! Why not? That laser was lined up PERFECTLY with the crosshairs! The problem is, the laser is CLOSE to where the bore is really pointing. Right now, chances are your bullets will land ON THE TARGET. That is what we want!
So what now?
We zero it manually! First a lesson on what Minute of Angle (MOA) is. MOA is equal to 1 inch at 100 yards. So if you are shooting 1 inch left of the bullseye, you are 1 MOA left. Your most common scope has an adjustment level of 1/4 MOA. This means if you turn your windage 4 notches left, you have moved your point of impact 1 inch in that direction if you are shooting on a target 100 yards away. 500 yards away? 4 clicks is going to move you 5 inches. 1000 yards? 10 inches.
So, you’re aiming at your target. Bore sight was finished long ago. You pull your trigger. Individual rounds don’t count. Only where your GROUPS are. With that in mind, make 2 more shots. How close are your rounds to EACH OTHER? If they are close, that means you’re shooting accurately. Your RIFLE isn’t, but you’re doing the work properly. Find the CENTER of your shot group. You look through the scope after you recover from the recoil and you see your group 2.5 inches UP and 3 inches LEFT of your target. Most people say to work on windage first, then work on elevation (or vice versa) but not both at the same time. I agree with this just because it prevents you from mixing things up. Let’s hit windage first. Your group is 3 inches to the left. You need to move it 3 inches to the right in order for it to be directly vertical to your bullseye. If 4 clicks means 1 inch at 100 yards, how are you going to move your shot group to the right? 12 clicks right should do it. Take another 3 shots and repeat until your groups are perfectly vertical of the bullseye.
Now, you have to move the round DOWN until you’re on target. If done properly, your round is now 2.5 inches above the bullseye and perfectly centered horizontally. Let’s move your round onto the bullseye. 2.5 inches, 4 clicks per inch, you’re looking at 4 x 2.5 = 10 clicks. Move your scope down 10 clicks. 3 more shots. Is your shot group on the bullseye? If not, repeat until it is. If it IS on the bullseye, congratulations! You’ve just zeroed your rifle for the 100 year line! You can now say with confidence that with the current settings, your groups should always be spot on assuming YOU are doing YOUR job with the aiming.
These settings are always your starting point when shooting at other distances as well. Let’s take the 300 yard line as an example. If you point your rifle down range at a target 300 yards away and pull the trigger, since you haven’t changed your zero (also called your dope), you should still be SPOT ON, right? No. When you throw a baseball, does it fly in a perfectly straight line? No, it drops more the further it flies. This is the trajectory. Bullets are definitely not immune to the laws of physics. (“Obey physics… IT’S THE LAW!”) You need to use your elevation to compensate for this bullet drop. Here is a table for 155gr .308.
RANGE DROP
100 0"
200 2.87"
300 11.2"
400 25.6"
500 46.9"
600 76.0"
700 114.9"
800 161.7"
This means if you are shooting at 300 yards, your bullet will hit 11.2 inches below the target. You have to move it 11.2 inches UP. We know that 4 clicks is 1 inch at 100 yards. If we’re moving it 11.2 inches, that means 45 clicks up right? NO! At 300 yards, 4 clicks is THREE inches. You need to take it up about 15 clicks. If 1 click = 1/4 in at 100 yards, then it equals 3/4 inch at 300 yards.
So your zero at 100 yards gives you a baseline. If you move to the 300 yard line, you have to move your round up 11.2 inches if using a 155gr .308. If you move to the 700 yard line, be prepared to move your round up 76.0 inches. Obviously different sized bullets, different amounts of powder, and different calibers will give you slightly different results.
Wind also has drastic effects on the bullet. The further out your target is, the longer the wind has to affect the path of your bullet, pushing it left or right. Wind coming STRAIGHT AT YOU or wind that is traveling WITH the bullet do not have a measurable effect on the path of the bullet. Only wind coming from the side in any measurable fashion. The amount that you will have to adjust varies very widely depending on the size of the bullet, the caliber of the round, and the amount of powder propelling it. That is far beyond the scope of this article.
For extra information (or if you’re not yet confused enough), check this link:
http://demigodllc.com/articles/practical-long-range-rifle-shooting-optics/
The above article is copied almost ver batim from something written by me over here: http://www.utahconcealedcarry.com/viewtopic.php?f=3&t=11301 Copy and use the information however you want!
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