laser bore sighting

gunenthusiast · October 29, 2008, 05:22 PM

I recently bought a rifle and later on I bought a scope. I want to install the scope and boresight it myself, therefore, I have been doing some reading on the subject. I checked out several bore sighting products and techniques, I watched several videos on how to bore sight a scope. Some sure make it look very simple.
However, I have a question for which I cannot find the answer, I hope that the knowledge and experience of the members of this forum will give solice to my curiosity.

Is the distance at which the target is placed important in the process of boresighting? If that is the case ( I assume it is) why do they put the target at any random distance, like the wall across the room, instead of going to the range or open field and actually measure 100 yards?

Thank you in advance for your input.
Rick

azredhawk44 · October 29, 2008, 05:34 PM

Distance doesn't really matter because bore-sighting is not truly sighting in.

I boresight across my house, about 50 feet or so.

Pull the bolt so you can look through the barrel, and line the barrel up on a target at the opposite end of the house. A piece of paper works good for this. Hang a plumb-bob or weighted string down the center of the paper for a vertical reference, or use a door-frame.

Adjust the scope in its mounts as needed and available to get the vertical stadia of the reticle to be parallel to the weighted string. Get the crosshairs more or less on the same spot you see when looking down the barrel.

Don't get anal about details, just get it more or less on the same point give or take an inch or two.

Go to the range and shoot at 25 yards. Fire a good group of 5. Adjust as needed, multiplying your measurements by 4 to find the MOA difference at 100 yards. Shoot again. On target? Good. Run the target out to 100 (or desired distance) and fine tune. Confirm zero, and use rifle as intended.

ETA: The lasers in those kits aren't necessarily going to be perfectly aligned down the bore. They can be off a couple of minutes of angle (or a couple dozen) and still exit the barrel without being too far off. Good tools, but by no means exactly precise.

Boresighting is just for getting on paper at the range. It should never be construed as truly being sighted in.

JayD976 · October 29, 2008, 05:51 PM

hang up a target at around 25-50ft or so away take the bolt out of your gun so you can line up the denter of the target with the barrel. Then look through the scope and adjust it until the crosshairs are on target thats should be enough till you fine tune it at the range.

Swampghost · October 29, 2008, 07:06 PM

As stated but I do it in the yard @ about 30 yds.

Mark the bore sight with a magic marker on one side so that you can rotate it semi-accurately. Check with mark up/down and side to side and you'll be much closer when you get to the range. A few shots @ 50 yds and a few more @ 100 should get you pretty close.

skeeter1 · October 29, 2008, 07:59 PM

I've got a Bushnell laser bore sight, and used it across the house, which gave me a 40' distance, and I was *WAY* off. The rifle (Marlin 1894C .357Mag) was shooting much too high. Once I learned how to use it properly, I was in the ballpark. It was only about $30, and worth the money, but nothing beats some range time with a screwdriver to finish up the job. Now the gun is shooting POI at 60-75yds, about all that I care about. It would have been much less complicated if I were setting up iron sights, but I was trying to install a new scope.

Still, once I figured out how to use it properly, I used it when putting a new red-dot on one of the .22s, and was spot-on right off the bat. It was worth it. Fit's everything from .22 to .50 just as long as the barrel is at least 4" long.

cecILL · October 30, 2008, 08:06 AM

Also, you can bag your rifle, take one shot at target at 25 yards. Realign crosshairs on target, and adjust scope to the hole you just made.

Alleykat · October 30, 2008, 08:31 AM

Quote:

Also, you can bag your rifle, take one shot at target at 25 yards. Realign crosshairs on target, and adjust scope to the hole you just made.

Exactly! Way too much fretting and "researching" a truly simple undertaking.

October 29, 2008, 05:22 PM	#1
gunenthusiast Junior Member Join Date: October 29, 2008 Posts: 1	laser bore sighting I recently bought a rifle and later on I bought a scope. I want to install the scope and boresight it myself, therefore, I have been doing some reading on the subject. I checked out several bore sighting products and techniques, I watched several videos on how to bore sight a scope. Some sure make it look very simple. However, I have a question for which I cannot find the answer, I hope that the knowledge and experience of the members of this forum will give solice to my curiosity. Is the distance at which the target is placed important in the process of boresighting? If that is the case ( I assume it is) why do they put the target at any random distance, like the wall across the room, instead of going to the range or open field and actually measure 100 yards? Thank you in advance for your input. Rick

October 29, 2008, 05:51 PM	#3
JayD976 Member Join Date: August 16, 2008 Location: Long Island, NY Posts: 52	hang up a target at around 25-50ft or so away take the bolt out of your gun so you can line up the denter of the target with the barrel. Then look through the scope and adjust it until the crosshairs are on target thats should be enough till you fine tune it at the range. __________________ Weatherby Vanguard .308 Remington 597 .22lr Mossberg 500 12ga

October 29, 2008, 07:06 PM	#4
Swampghost Senior Member Join Date: April 18, 2008 Location: Florida, east coast Posts: 2,106	As stated but I do it in the yard @ about 30 yds. Mark the bore sight with a magic marker on one side so that you can rotate it semi-accurately. Check with mark up/down and side to side and you'll be much closer when you get to the range. A few shots @ 50 yds and a few more @ 100 should get you pretty close. __________________ NRA Patron Member

October 29, 2008, 07:59 PM	#5
skeeter1 Senior Member Join Date: April 11, 2006 Location: Northeast Ohio Posts: 3,403	Laser boresight? I've got a Bushnell laser bore sight, and used it across the house, which gave me a 40' distance, and I was WAY off. The rifle (Marlin 1894C .357Mag) was shooting much too high. Once I learned how to use it properly, I was in the ballpark. It was only about $30, and worth the money, but nothing beats some range time with a screwdriver to finish up the job. Now the gun is shooting POI at 60-75yds, about all that I care about. It would have been much less complicated if I were setting up iron sights, but I was trying to install a new scope. Still, once I figured out how to use it properly, I used it when putting a new red-dot on one of the .22s, and was spot-on right off the bat. It was worth it. Fit's everything from .22 to .50 just as long as the barrel is at least 4" long.

October 29, 2008, 05:34 PM	#2
azredhawk44 Junior member Join Date: September 28, 2005 Location: Mesa, AZ Posts: 6,465	Distance doesn't really matter because bore-sighting is not truly sighting in. I boresight across my house, about 50 feet or so. Pull the bolt so you can look through the barrel, and line the barrel up on a target at the opposite end of the house. A piece of paper works good for this. Hang a plumb-bob or weighted string down the center of the paper for a vertical reference, or use a door-frame. Adjust the scope in its mounts as needed and available to get the vertical stadia of the reticle to be parallel to the weighted string. Get the crosshairs more or less on the same spot you see when looking down the barrel. Don't get anal about details, just get it more or less on the same point give or take an inch or two. Go to the range and shoot at 25 yards. Fire a good group of 5. Adjust as needed, multiplying your measurements by 4 to find the MOA difference at 100 yards. Shoot again. On target? Good. Run the target out to 100 (or desired distance) and fine tune. Confirm zero, and use rifle as intended. ETA: The lasers in those kits aren't necessarily going to be perfectly aligned down the bore. They can be off a couple of minutes of angle (or a couple dozen) and still exit the barrel without being too far off. Good tools, but by no means exactly precise. Boresighting is just for getting on paper at the range. It should never be construed as truly being sighted in.

October 30, 2008, 08:06 AM	#6
cecILL Senior Member Join Date: August 13, 2001 Location: central IL Posts: 769	Also, you can bag your rifle, take one shot at target at 25 yards. Realign crosshairs on target, and adjust scope to the hole you just made.