Bore Sighting Basics

[elkhunter11]

Bore sighting Tirebobs scope Thursday, he asked some questions that many people ask , so I will go over some of the basics. I start by placing the rifle on my shooting rest and bags, remove the bolt, and look down the bore, and center the target in the bore. Then I adjust the scope, until the crosshairs are centered on the same target as the bore. It can be confusing, if the crosshairs are high, you turn the adjustment as you would to move the point of impact higher. You do this, because although you are moving the crosshairs, the scope is marked to move the point of impact. If the crosshairs are to the right, you turn the adjustment to move the point of impact to the right.
I typically boresight at 100m, and the first shot at 100m is normally within 2-3" of the bullseye, as was the case Thursday, with Tirebob's rifle/scope. I then usually make one coarse adjustment, and then fire a three shot group. The amount that the point of impact is supposed to move at 100 yards, per click, is usually marked on the adjuster. If you are not shooting at 100 yards, you need to compensate based on basic geometry. Then if required, I make a fine adjustment and shoot another three shot group, and the rifle is sighted in with seven shots. Tirebob was hitting dead center bullseye after four shots, although I did make an adjustment, when he changed loads, as two loads shot to the same point of impact, but over an inch from the first load we tried.

[CNP]

I do the bore sighting at home before going to the range. Lock the rifle down in the Tipton Gun Vise. Remove the bolt. Look down the bore and place the door bell button at my neighbours house, 50 yards away, in the centre of the bore and adjust the scope to match. All set to go to the range

JK.......replace door bell button at my neighbours house with the 1.75" opening I have drilled in my bird house. All set to go to the range

[Demonical]

I pull out the bolt, put the gun on the bags, sight down the barrel center on the target bullseye, then look at the scope, (without moving the rifle of course).

Adjust the crosshairs to the center of the bullseye.

Works excellent and there is zero cost.

[elkhunter11]

The best part of doing a good job bore sighting, is that you don't waste time and ammunition shooting at 25m or 50m, your first shot is on the paper at 100m.

[OL_JR]

Originally Posted by CNP

I do the bore sighting at home before going to the range. Lock the rifle down in the Tipton Gun Vise. Remove the bolt. Look down the bore and place the door bell button at my neighbours house, 50 yards away, in the centre of the bore and adjust the scope to match. All set to go to the range

JK.......replace door bell button at my neighbours house with the 1.75" opening I have drilled in my bird house. All set to go to the range

Pretty much do it the exact same way with the exact same rest only difference is that I use a spot on the neighbours garage door across the alley lol.

Pulling the bolt is easily the most accurate way to sight in a bolt gun imho. I would never recommend not checking at the range after bore sighting but the guns I've bore sighted this way I could hunt with after. If you really take the time to make sure the inside of the barrel is even all the way around with the target in the exact center it is amazing how close you can get. Good post elkhunter.

[Dick284]

Same process I do with all bolt guns.
And if it takes more than 4 shots to get a rifle to a hunt able setting something isn’t quite right.

Interestingly this exact process is laid out in every scope owners manual I’ve ever looked at.

[elkhunter11]

Originally Posted by Dick284

Same process I do with all bolt guns.
And if it takes more than 4 shots to get a rifle to a hunt able setting something isn’t quite right.

Interestingly this exact process is laid out in every scope owners manual I’ve ever looked at.

And yet I regularly see people waste two boxes of ammunition, getting on the paper, and chasing the point of impact around the target, then they run out of ammunition, and declare that they are close enough to hunt.

[catnthehat]

Boresighting through the barrel I can normally get on the 24" steel at 200 meters in two shots at our range , the third will impact at point if aim .
New gun owners always seem to be amazed, but most times they have been talking to people that really don't know how to properly set up a rifle and bore sight it
Cat

[DLab]

Originally Posted by elkhunter11

And yet I regularly see people waste two boxes of ammunition, getting on the paper, and chasing the point of impact around the target, then they run out of ammunition, and declare that they are close enough to hunt.

Ain't that the truth.
I'm fairly certain I could fill a 2 page thread with things I've heard and seen done by people sighting in rifles at the range that make me shake my head in wonder and amusement, at times almost cringe painful to watch.

[Pathfinder76]

Bore sight. Shoot. Adjust. I quite often shoot two after the initial adjustment. But two were good enough that I couldn’t resist three. I’ll fine tune at distance. :-)

[Twisted Canuck]

I thought you didn't drink coffee Chuck? That group looks a bit shaky for you.

[Pathfinder76]

Likely the Coke Zero.

[cowmanbob]

Let’s see if anyone can answer this. Most of my rifles sighted in look the part when looking through the bore. A few of them look way off while bore sighting while being dead on.

[catnthehat]

Originally Posted by cowmanbob

Let’s see if anyone can answer this. Most of my rifles sighted in look the part when looking through the bore. A few of them look way off while bore sighting while being dead on.

Could be something as simple as the hight of the scope above the bore, I have noticed the same thing at times but once they are bore sighted , in the wirds of Donny Brascoe, fogetabpoutit, just change thevsope turrets as needed
Cat

[cowmanbob]

All low rings and it’s always a sideways thing.

[elkhunter11]

Originally Posted by cowmanbob

All low rings and it’s always a sideways thing.

Could it be that you can't get your eye centered directly behind the bore because of the comb, so you are off to one side?

[cowmanbob]

Originally Posted by elkhunter11

Could it be that you can't get your eye centered directly behind the bore because of the comb, so you are off to one side?

Nope.

[elkhunter11]

Originally Posted by cowmanbob

Nope.

The rifle that we sighted in Thursday saw a horizontal change of over two inches, when we changed from one 180gr load to another 180gr load, so if it's only a few inches, it may be nothing more than harmonics. Even if your boresighting was perfect, it can't account for harmonics.
Personally, I find that other than usually being slightly low, which I attribute to bullet drop, the horizontal differences are usually random, sometimes slightly left, sometimes slightly right, and sometimes pretty much centered.

[Pathfinder76]

Originally Posted by cowmanbob

Nope.

Does your gun shoot around corners?

[cowmanbob]

The one rifle in question is a HS precision. I’ve shot one inch groups at 200 yds with it.

[Pathfinder76]

I suspect it might be a parallax thing. It is actually quite tough to get straight behind a scope sometimes while trying not to touch anything.