Why do I need to bore-sight?
Many years and mistakes ago, I found myself at a local sporting goods store. Nothing fancy at all, it was basically like a K-Mart where they sold Mossbergs, baseball gloves, and golf club sets. Being a complete novice in the shooting arts at the time, I peered covetously over the collection of boring-ass three-hundred-dollar production rifles on the shelves. If only I’d known back then what a collection of amazing rifles I would one day enjoy.
Among all the cheap pocket knives and leather slings hanging on the shelves, I noticed a strange apparatus called a “bore-sighting-tool.” I had no idea what it was, it appeared to have some sort of lens in it, so I assumed it had something to do with sighting in a rifle.
Fast forward a few years, and I had learned a bit more about rifles, shooting and everything involved in it. I was still what I considered a novice at the time, and I was out shooting with my Grandfather. While trying to zero a scope, Grandpa explained to me the way he used to sight in his Howitzer back in the war between Korea’s. Using a distant point, preferably a star Grandpa said, he would center the point in the middle of his 105mm bore. Once it was centered, he could adjust the sight to the same point of aim, and that would give a good starting point to work from. This lesson stuck with me ever since, it was easily digested by my Neanderthal brain.
The first thing you will need to do is find a VERY stable position to set your rifle up, and remove the bolt. I usually use a good bipod on the front and either sandbags or a good shooting rest or monopod on the back. Whatever you use, make sure that the rifle is as stable as possible with no movement (perhaps even in a vise if you have the option). The bench at the rifle range works great if you have everything you need to keep it stable. You’ll want to set the rifle up so that the bore of the rifle is looking at your point of focus, that might be the bullseye of your target, or a distant rock or tree on a hillside.
Adjust your sandbags or whatever you are using, so that your focal point is perfectly centered in your rifle-bore. The key is to get it as centered as possible, that means you want your eye perfectly positioned behind the rifle’s bore. The easiest way to confirm that is by moving your head up and down, and side to side until you find that perfect spot where the breach, bore, and muzzle of the rifle are all concentric with each other.
They should look like a circle, centered in another circle, centered in yet another circle. And when you have that figured out, adjust your rifle until your point is as close to the center of the rifle’s bore as possible. Once you have it set, double check a few times and make sure it’s perfect. The next step is to adjust the turrets of your rifle scope to center the reticle on the same exact focal point.
If you your turrets are capped, it would be best to de-cap the turrets prior to this point to minimize movement of the rifle, and now you can see why you want the rifle as solid as possible prior to starting. If the movement of the turrets shifts the rifle in anyway, you’ll have to start over again.
Carefully adjust the reticle to your focal point, and double check your bore to ensure that it still remains centered. Once you have both your reticle and bore centered on the same distant point, you are ready to put your bolt back in, and start shooting. Sometimes the point of impact is near perfect, and other times it may take a few shots to perfect your zero. But you will definitely be on a sheet of paper if you’ve done it right.
I’ve done it this way for decades now, and it has never failed me yet. I can usually take a new rifle and scope to the range and within as little as two or three shots have a solid zero. I never actually used one of the bore-sighting tools that I used to see in the stores, and I certainly don’t need to spend money on one.
This of course is not the only way to do it, and perhaps not even the best, but it works. Hopefully you’ll find this practice as useful as I have, and with any luck you will get it right the first time. But if not, just keep trying until you get the hang of it.